Delphi (programming language)

Embarcadero Delphi is an integrated development environment (IDE) for console, desktop graphical, web, and mobile applications.^[1]

Delphi's compilers use their own Object Pascal dialect of Pascal and generate native code for several platforms: Windows NT (IA-32 and x64), OS X (IA-32 only), iOS and Android.

Delphi was originally developed by Borland as a rapid application development tool for Windows, and as the successor of Borland Pascal. Delphi and its C++ counterpart, C++Builder, shared many core components, notably the IDE and the Visual Component Library (VCL), but remained separate until the release of RAD Studio 2007. RAD Studio is a shared host for Delphi, C++Builder, and others.

In 2006, Borland’s developer tools section were transferred to a wholly owned subsidiary known as CodeGear, which was sold to Embarcadero Technologies in 2008.

History

Delphi was originally one of many codenames of a pre-release development tool project at Borland. Borland developer Danny Thorpe suggested the Delphi codename in reference to the Oracle at Delphi. One of the design goals of the product was to provide database connectivity to programmers as a key feature and a popular database package at the time was Oracle database; hence, "If you want to talk to [the] Oracle, go to Delphi".

As development continued towards the first release, the Delphi codename gained popularity among the development team and beta testing group. However, the Borland marketing leadership preferred a functional product name over an iconic name and made preparations to release the product under the name "Borland AppBuilder".

Shortly before the release of the Borland product, Novell AppBuilder was released, leaving Borland in need of a new product name. After much debate and many market research surveys, the Delphi codename became the Delphi product name.^[2]

The chief architect behind Delphi was Anders Hejlsberg, who had developed Turbo Pascal. He was persuaded to move to Microsoft in 1996.

On February 8, 2006 Borland announced that it was looking for a buyer for its IDE and database line of products, including Delphi, to concentrate on its ALM line. On November 14, 2006 Borland transferred the development tools group to an independent subsidiary company named CodeGear, instead of selling it.^[3] Borland sold CodeGear to Embarcadero Technologies in 2008. Embarcadero retained the CodeGear division created by Borland to identify its tool and database offerings, but identified its own database tools under the DatabaseGear name.

Versions

Inprise Delphi 4.0.

Early Borland years (1995-2004)

Borland Delphi

Delphi (later known as Delphi 1) was released in 1995 for the 16-bit Windows 3.1, and was an early example of what became known as Rapid Application Development (RAD) tools. Delphi evolved from Borland's "Turbo Pascal for Windows", itself an evolution with Windows support from Borland's Turbo Pascal and Borland Pascal, very fast 16-bit native-code MS-DOS compilers with their own sophisticated integrated development environment (IDE) and textual user interface toolkit for DOS (Turbo Vision). Early Turbo Pascal (for MS-DOS) was written in a dialect of the Pascal programming language; in later versions support for objects was added, and it was named Object Pascal. Delphi has always used Object Pascal, which continued to be developed, as its underlying object-oriented language.

Borland Delphi 2

Delphi 2, released in 1996, supported 32-bit Windows environments. Delphi 1 was bundled with it for creation of 16-bit Windows 3.1 applications. New Quickreport components replacing Borland ReportSmith. It was then later turned into Java.

Borland Delphi 3

Delphi 3, released in 1997, added new VCL components encapsulating the 4.71 version of Windows Common Controls (such as Rebar and Toolbar), TDataset architecture separated from BDE, DLL debugging, the code insight technology, component packages, component templates, DecisionCube and Teechart components for statistical graphing, WebBroker, ActiveForms, MIDAS three tier architecture, component packages and integration with COM through interfaces.

Inprise Delphi 4

Inprise Delphi 4 was released in 1998. IDE came with a completely overhauled editor and became dockable. VCL added support for ActionLists anchors and constraints. Additional improvements were method overloading, dynamic arrays, Windows 98 support, Java interoperability, high performance database drivers, CORBA development, and Microsoft BackOffice support. It was the last version shipped with Delphi 1 for 16 bit programming.

Borland Delphi 5

Borland Delphi 5 was released in 1999. Added concept of frames, parallel development, translation capabilities, enhanced integrated debugger, XML support, ADO database support and reference counting interfaces

Kylix

In 2001 Borland released a Linux version of Delphi, named Kylix. To get a product out quickly and cheaply, they made the IDE depend on the Wine libraries rather than Linux's native system libraries (glibc). The expense of developing a native glibc version of Kylix, combined with the lack of Linux adoption among programmers at the time, made sales go soft, and Kylix was abandoned after version 3. This was the first attempt to add Linux support in the Delphi product family.

Kylix used the new CLX cross-platform framework, instead of Delphi's VCL.

Borland Delphi 6

Attempts to support both Linux and Windows for cross-platform development were made, and a cross-platform alternative to the VCL known as CLX shipped in 2001 with the release of Delphi 6. This was the second attempt to add Linux support to the Delphi product family (see Kylix above).

Delphi 6 included the same CLX version (CLX 1) as the first version of Kylix. CLX 1 had been created before Delphi 6; its feature set was based on VCL 5 and lacked some features added to the VCL 6 shipped with Delphi 6.^[4]

Borland Delphi 7

Delphi 7, released in August 2002, became the standard version used by more Delphi developers than any other single version. It is one of the most successful IDEs created by Borland because of its stability, speed and low hardware requirements, and remained in active use as of 2011.^[5] Delphi 7 added support for Windows XP Themes, and added more support for building Web applications. It was the last version of Delphi that did not require mandatory software activation.

Borland Delphi 8

Delphi 8, released December 2003, was a .NET-only release that compiled Delphi Object Pascal code into .NET CIL; the IDE was rewritten for this purpose. The IDE changed to a docked interface (called Galileo) similar to Microsoft's Visual Studio.NET. Delphi 8 was highly criticized for its low quality and its inability to create native applications (Win32 API/x86 code). The inability to generate native applications is only applicable to this release; the capability was restored in the next release (Delphi 2005).

Later Borland years (2004-2008)

Borland Delphi 2005

The next version, Delphi 2005 (Delphi 9, also Borland Developer Studio 3.0), included the Win32 and .NET development in a single IDE, reiterating Borland's commitment to Win32 developers. Delphi 2005 includes design-time manipulation of live data from a database. It also includes an improved IDE and added a for ... in statement (like C#'s foreach) to the language. However, it was widely criticized^[6] for its bugs; both Delphi 8 and Delphi 2005 had stability problems when shipped, which were only partially resolved in service packs. The ability to compile native windows applications (*.exe) was added back into Delphi 2005 after being removed in Delphi 8. CLX support was dropped for new applications from this release onwards.

Borland Delphi 2006

In late 2005 Delphi 2006 (Delphi 10, Borland Developer Studio 4.0) was released and combined development of C# and Delphi.NET, Delphi Win32 and C++ (Preview when it was shipped but got stable in Service Pack 1) into a single IDE. It was much more stable than Delphi 8 or Delphi 2005 when shipped, and improved even more with the release of service packs and several hotfixes.

Turbo Delphi and C++

On September 6, 2006 The Developer Tools Group (the working name of the not yet spun off company) of Borland Software Corporation released single-language versions of Borland Developer Studio components, bringing back the Turbo name. The Turbo product set included Turbo Delphi for Win32, Turbo Delphi for .NET, Turbo C++, and Turbo C#. There were two variants of each edition: Explorer, a free downloadable version, and the Professional version, priced at US$899 for new users and US$399 for updates, less than the full Borland Delphi, which opened access to thousands of third-party components. Unlike earlier Personal editions of Delphi, Explorer editions could be used for commercial development.

Codegear Delphi 2007

Photo of Delphi 2007 box as released by CodeGear in spring 2007.

Delphi 2007 (Delphi 11), the first version by CodeGear, was released on March 16, 2007. The Win32 personality was released first, before the .NET personality of Delphi 2007 based on .NET Framework 2.0 was released as part of the CodeGear RAD Studio 2007 product. New features included support for MSBuild and enhancements to the VCL for Windows Vista, but the C#Builder feature was dropped in this release as sales where not as high as expected due to Visual Studio also offering C#. The Windows Form designer for Delphi .NET was also dropped in 2007 because it is based on part of the .NET framework API, which Microsoft had changed so drastically in .NET 2.0 that updating the IDE would have been a major undertaking. Delphi 2007 also introduced DBX4 as the next version of dbExpress. For the first time Delphi could be downloaded from the Internet and activated with a license key, a capability powered by the new InstallAware installation technology (itself authored in Delphi, and now shipping in a free, limited edition inside the box with Delphi). Internationalized versions of Delphi 2007 shipped simultaneously in English, French, German and Japanese. RAD Studio 2007 (code named Highlander), which includes .NET and C++Builder development, was released on September 5, 2007.

Delphi Prism

Delphi Prism was developed by RemObjects Software and distributed by Embarcadero from 2008 to replace Delphi.NET. It is a combination of RemObjects's mostly Delphi-compatible .NET compiler (without RTL or VCL), a version of the Microsoft Visual Studio Shell without C# or VB support, and some Embarcadero technologies such as dbExpress. Prism is cross-platform capable insofar as it supports the Mono .NET libraries. Prism is a separate product line with new releases; Embarcadero Delphi Prism XE2 was released at about the same time as Delphi XE2.^[7]

Embarcadero years (2008-2015)

Embarcadero Delphi 2009

Delphi 2009 (Delphi 12, code named Tiburón), added many new features such as completely reworking the VCL and RTL for full Unicode support, and added generics and anonymous methods for Win32 native development. Support for .NET development was dropped from the mainstream Delphi IDE starting with this version, and was catered for by the new Delphi Prism.^[8]

Embarcadero Delphi 2010

Delphi 2010 (code-named Weaver, aka Delphi 14; there was no version 13), was released on August 25, 2009 and is the second Unicode release of Delphi. It includes a new compiler run-time type information (RTTI) system,^[9] support for Windows 7 direct 2D, touch screen and gestures, a source code formatter, debugger visualizers and the option to also have the old style component palette in the IDE. The new RTTI system makes larger executables than previous versions.^[10]

Embarcadero Delphi XE

Delphi XE (aka Delphi 2011,^[11] code named Fulcrum), was released on August 30, 2010 with Delphi support for Amazon EC2, Microsoft Azure were bundled.^[12]

Delphi Starter Edition

On January 27, 2011 Embarcadero announced the availability of a new Starter Edition that gives independent developers, students and micro businesses a slightly reduced feature set^[13] for a price less than a quarter of that of the next-cheapest version.^[14]

Embarcadero Delphi XE2

RAD Studio XE2 World Tour

On September 1, 2011 Embarcadero released RAD Studio XE2 (code-named Pulsar,^[15]) which included Delphi XE2, C++Builder, Prism XE2 and RadPHP XE2.^[16]

Delphi XE2 natively supports 64-bit Windows (except the starter edition), in addition to the long-supported 32-bit versions, with some backwards compatibility. Applications for 64-bit platforms can be compiled, but not tested or run, on the 32-bit platform.^[17] The XE2 IDE cannot debug 64-bit programs on Windows 8 and above.

Delphi XE2 is supplied with both the VCL, and an alternative library called FireMonkey^[17] that supports Windows, Mac OS X and the Apple iPhone, iPod Touch and iPad portable devices.^[18] FireMonkey and VCL are not compatible; one or the other must be used, and older VCL applications cannot use Firemonkey unless user interfaces are recreated with FireMonkey forms and controls. Third parties have published information on how to use Firemonkey forms in VCL software, to facilitate gradual migration, but even then VCL and Firemonkey controls cannot be used on the same form.^[19] Embarcadero says that Linux operating system support "is being considered for the roadmap", as is Android, and that they are "committed to ... FireMonkey. ... expect regular and frequent updates to FireMonkey".^[17]

Pre-2013 versions only supported iOS platform development with Xcode 4.2.1 and lower, OS X version 10.7 and lower, and iOS SDK 4.3 and earlier.

Embarcadero Delphi XE3

On September 4, 2012 Embarcadero released RAD Studio XE3, which included Delphi XE3, and C++Builder.

Delphi XE3 natively supports both 32-bit and 64-bit editions of Windows (including Windows 8), and provides support for Mac OS X with the Firemonkey 2/FM² framework. iOS support was dropped with XE3 release initially (with intent to add support back in with a separate product - Mobile Studio), but applications can continue to be targeted to that platform by developing with Delphi XE2.

Embarcadero Delphi XE4

On April 22, 2013 Embarcadero released RAD Studio XE4, which included Delphi XE4, and C++Builder.

Delphi XE4 is the first release of the FireMonkey mobile platform, featuring cross-platform mobile application development for the iOS Simulator and iOS Devices.

In this version Embarcadero introduces two new compilers for Delphi mobile applications, the Delphi Cross Compiler for the iOS Simulator and the Delphi Cross Compiler for the iOS Devices. These compilers significantly differ from the Win64 desktop compiler as they do not support COM, inline assembly of CPU instructions, and six older string types such as PChar.^[20]

The new mobile compilers advance the notion of eliminating pointers. The new compilers require an explicit style of marshalling data to and from external APIs and libraries.^[21]

Delphi XE4 Run-Time Library (RTL) is optimized for 0-based, read-only (immutable) Unicode strings, that cannot be indexed for the purpose of changing their individual characters. The RTL also adds status-bit based exception routines for ARM CPUs that do not generate exception interrupts.^[21]

Embarcadero Delphi XE5

On September 12, 2013 Embarcadero released RAD Studio XE5, which includes Delphi XE5 and C++Builder.

It adds support for Android (specifically: ARM v7 devices running Gingerbread (2.3.3-2.3.7), Ice Cream Sandwich (4.0.3-4.0.4) and Jelly Bean (4.1.x, 4.2.x, 4.3.x))^[22] and iOS 7.

Embarcadero Delphi XE6

On April 15, 2014 Embarcadero released RAD Studio XE6, which included Delphi XE6 and C++Builder.

It allows to create natively-compiled apps for all platforms for, desktop, mobile, and wearable devices like Google Glass, with a single C++ or Object Pascal (Delphi) codebase. RAD Studio XE6 adds support for Android 4.4 KitKat. It also became possible to create FireMonkey mobile apps for Android.^[23]

Embarcadero Delphi XE7

On September 2, 2014 Embarcadero released RAD Studio XE7, which included Delphi XE7 and C++Builder.

It enables Delphi/Object Pascal and C++ developers to extend existing Windows applications and build apps that connect desktop and mobile devices with gadgets, cloud services, and enterprise data and APIs. Also, it enables developers to extend Windows applications using WiFi and Bluetooth App Tethering, and create shared user interface code across multiple device form factors, etc.^[24]

Embarcadero Delphi XE8

On April 7, 2015 Embarcadero released RAD Studio XE8, which included Delphi XE8 and C++Builder.^[25]

Embarcadero Delphi 10 Seattle

On August 31, 2015 Embarcadero released RAD Studio 10 Seattle, which included Delphi and C++Builder.

Roadmaps

Embarcadero publishes "roadmaps" describing their plans.^[26][27]

Editions and prices

Each version has been released in different editions, which add features and price to the most basic release. As an indication of editions and prices, Delphi XE2 was sold directly by Embarcadero in 2011 in editions called Starter (US$199), Professional ($899), Enterprise ($1,999), Ultimate ($2,999), and Architect ($3,499).^[28] Prices vary from different suppliers, with different incentives, and in different regions, and Delphi is also included in the RAD Studio bundles. Embarcadero publishes feature matrices summarising the differences in functionality.^[1]

Distinguishing features

Delphi supports rapid application development (RAD). Among features supporting RAD are application framework]] and visual window layout designer. It supports native cross-compilation.

Delphi uses the Pascal-based programming language called Object Pascal introduced by Borland, and compiles Delphi source code into native x86 code. It includes VCL, support for COM independent interfaces with reference counted class implementations, and support for many third-party components. Interface implementations can be delegated to fields or properties of classes. Message handlers are implemented by tagging a method of a class with the integer constant of the message to handle.

Database connectivity is supported, and Delphi supplies several database components. VCL includes many database-aware and database access components.

Later versions have included upgraded and enhanced Runtime Library routines provided by the community group FastCode, established in 2003.

Characteristics

Delphi is a strongly typed high-level programming language, intended to be easy to use and originally based on the earlier Object Pascal language. Pascal was originally developed as a general purpose language "suitable for expressing the fundamental constructs known at the time in a concise and logical way", and "its implementation was to be efficient and competitive with existing FORTRAN compilers" ^[29] but without low-level programming facilities or access to hardware. Turbo Pascal and its descendants, including Delphi, support access to hardware and low level programming, with the facility to incorporate code written in assembly language and other languages. Delphi's object orientation features only class- and interface-based polymorphism. Metaclasses are first class objects. Objects are actually references to the objects (as in Java), which Delphi implicitly de-references, so there is usually no need to manually allocate memory for pointers to objects or use similar techniques that some other languages need. There are dedicated reference-counted string types, and also null-terminated strings.

Strings can be concatenated by using the '+' operator, rather than using functions. For dedicated string types Delphi handles memory management without programmer intervention. Since Borland Developer Studio 2006 there are functions to locate memory leaks.

Delphi includes an integrated IDE. The Delphi products all ship with a Visual Component Library (VCL), including most of its source code. Third-party components (sometimes with full source code) and tools to enhance the IDE or for other Delphi related development tasks are available, some free of charge. The IDE includes a GUI for localization and translation of created programs that may be deployed to a translator; there are also third-party tools with more features for this purpose. The VCL framework maintains a high level of source compatibility between versions, which simplifies updating existing source code to a newer Delphi version. Third-party libraries may need updates from the vendor but, if source code is supplied, recompilation with the newer version may be sufficient. The VCL was an early adopter of Dependency injection or Inversion of Control; it uses a-"re-usable" component model, extensible by the developer. With class helpers new functionality can be introduced to core RTL and VCL classes without changing the original source code of the RTL or VCL.

The compiler is optimizing and single pass. It can optionally compile to a single executable which does not require DLLs, simplifying program updating. Delphi can also generate standard DLLs, ActiveX DLLs, COM automation servers and Windows services.

The Delphi IDEs since Delphi 2005 increasingly support refactoring features such as method extraction^[30] and the possibility to create UML models from the source code or to modify the source through changes made in the model.

Delphi has large communities on Usenet and the web. When Delphi was owned by Codegear, many of its employees actively participated.

Backward compatibility

Each new release of Delphi attempts to be as compatible as possible with earlier versions, so that already-developed software and libraries can be retained. Incompatibility necessarily arises as new functionality is added, e.g., with support by Firemonkey of other platforms than Windows.^[17]

Limitations

Backward compatibility^[31]

Each new release of Delphi attempts to keep as much backwards compatibility as possible to allow existing code reuse. The design of the standard class libraries (VCL/RTL) had become somewhat dated and restrictive; Embarcadero released in 2011 as part of Delphi XE2 a new compiler and cross-platform VCL replacement called FireMonkey,^[17] based on Direct3D and OpenGL, which runs on other platforms in addition to Windows, supporting their features, but is not fully backwards-compatible with VCL applications. FireMonkey applications do however allow easy sharing of non visual code units with VCL applications, enabling a lot of code to be ported easily between the platforms.

Issues

Some releases of Delphi were reported to be unstable. Delphi XE7, in particular, was often reported to be slow and subject to severe memory leaks.^[32]

Related software

RAD Studio

Embarcadero sells RAD Studio, a suite of development tools that consists of Delphi, C++Builder, Embarcadero Prism, and HTML5 Builder.^[33] Like Delphi, there are different editions of RAD Studio: Professional edition, Enterprise edition, Ultimate edition and Architect edition.^[34]

InterBase

InterBase integrates natively to Delphi and C++Builder for client/server or embedded development and can be accessed by all major languages and platforms in the market with database connection protocols like ODBC, ADO, ADO.NET and even with Java by JDBC/ODBC Bridge or Java type 4 connectors.

JBuilder

Tool for Java development based on Eclipse since version JBuilder 2007.^[35]

RadPHP (formerly Delphi for PHP)

RadPHP (now superseded by HTML5 Builder) was an IDE for PHP that provides true RAD functionality. It has a form designer similar to that of Delphi or Visual Basic, and an integrated debugger based on the Apache web server. It also includes a VCL library ported to PHP. Unlike other IDEs it supports Web 2.0 features such as AJAX.

Delphi for PHP was announced on March 20, 2007, renamed on October 2010 to RadPHP, and is based on Qadram Q studio. Embarcadero acquired Qadram in January 2011.

Delphi Prism

Delphi Prism (later known as Embarcadero Prism) derived from the Oxygene programming language (previously known as Chrome) from RemObjects. It ran in the Microsoft Visual Studio IDE rather than RAD Studio. It was licensed and re-branded by Embarcadero to replace Delphi.NET when that product was discontinued.

Although RemObjects Oxygene was further developed and incorporated support for native Java, Android, iOS and OS X development, the version licensed by Embarcadero was limited to only supporting .NET. It was eventually discontinued by Embarcadero with the release of Delphi XE4, leaving the Delphi product line with no support for .NET development.

The Oxygene product it was based on continues to be developed by RemObjects as part of their Elements product line.

Free Pascal and Lazarus

Free Pascal is an open-source Pascal cross-platform cross-compiler that supports most of Delphi's Object Pascal code. Lazarus is a cross-platform RAD IDE that uses the Free Pascal compiler. Lazarus and Free Pascal, free software independent of Embarcadero, is largely compatible with code written for Delphi.

Third-party libraries

• Project Jedi (Joint Endeavor of Delphi Innovators) - A collaborative open-source effort by the Delphi developer community to provide translations of Windows API interfaces, additional components and controls, and algorithms and data structures.
• FastCode - Enhanced runtime libraries and memory manager.
• Teechart - Charting library.
• OpenWire (library) - Data flow, events, and state synchronization component library.
• Bold for Delphi - Persistence mapper that support OCL and derivation.
• Quadruple D - DirectX library for Delphi

Code examples

To show a message:

procedure TForm1.ShowAMessage;
begin
  ShowMessage('Hello World!');
end;

To give a label a caption using the VCL:

procedure TForm1.ShowSomethingOnCreate;
begin
  Label1.Caption := 'Hello World!';
end;

To give a label text using FireMonkey:

procedure TForm1.ShowSomethingOnCreate;
begin
  Label1.Text := 'Hello World!';
end;

References

Further reading

External links

• Official website
• Delphi Basics Help and reference for the fundamentals of the Delphi
• Useful Sites - Delphi Programming

Pascal programming language family Dialects Pascal Object Pascal Pascal Script Oxygene Clascal Concurrent Pascal SuperPascal Compilers Current Delphi Oxygene PocketStudio HP Pascal IP Pascal Prospero Pascal Free Pascal (Lazarus) GNU Pascal Turbo51 MIDletPascal Pic Micro Pascal ACK Historical Virtual Pascal Apple Pascal Turbo Pascal Microsoft Pascal UCSD Pascal JRT Pascal/MT+ API CLX FCL FireMonkey LCL Object Windows Library OpenWire RTL Turbo Vision Visual Component Library Comparison of Pascal and C Comparison of Pascal and Delphi Related to: ALGOL (1958) Modula-2 (1977) Ada (1983) Oberon (1986) Modula-3 (1988) Oberon-2 (1991) Component Pascal (1991)