Editing Free Pascal (section)

== History ==

=== Early years ===
Free Pascal was created when Borland clarified that Borland Pascal development for [[DOS]] would stop with version 7, to be replaced by a [[Microsoft Windows|Windows]]-only product, which later became Delphi.

Student [[Florian Klämpfl|Florian Paul Klämpfl]] began developing his own compiler written in the Turbo Pascal dialect and produced [[32-bit]] code for the GO32v1 [[DOS extender]], which was used and developed by the DJ's GNU Programming Platform ([[DJGPP]]) project at that time.

Originally, the compiler was a [[16-bit]] DOS executable compiled by [[Turbo Pascal]]. After two years, the compiler was able to [[Bootstrapping (compilers)|compile itself]] and became a 32-bit executable.

=== Expansion ===
The initial 32-bit compiler was published on the [[Internet]], and the first contributors joined the project. Later, a [[Linux]] port was created by Michael van Canneyt, five years before the [[Borland Kylix]] Pascal compiler for Linux became available.

The DOS port was adapted for use in [[OS/2]] using the [[EMX (programming environment)|Eberhard Mattes eXtender]] (EMX) which made OS/2 the second supported compiling target. As well as Florian Klämpfl the original author, Daniël Mantione also contributed significantly to make this happen, providing the original port of the run-time library to OS/2 and EMX. The compiler improved gradually, and the DOS version migrated to the GO32v2 extender. This culminated in release 0.99.5, which was much more widely used than prior versions, and was the last release aiming only for Borland Pascal compliance; later releases added a Delphi compatibility mode. This release was also ported to systems using [[Motorola 68000 family]] (m68k) processors.

With release 0.99.8 the [[Win32]] target was added, and a start was made with incorporating some Delphi features. Stabilizing for a non-[[Software release life cycle|beta release]] began, and version 1.0 was released in July 2000. The 1.0.''x'' series<!--and the bug-fix/stabilization releases that followed, last, 1.0.10 in July 2003--> was widely used, in business and education. For the 1.0.''x'' releases, the port to 68k CPU was redone, and the compiler produced stable code for several 68k [[Unix-like]] and [[AmigaOS]] operating systems.

=== Version 2 ===
During the stabilization of what would become 1.0.''x'', and also when porting to the [[Motorola]] 68k systems, it was clear that the design of the code generator was far too limited in many aspects. The principal problems were that adding processors meant rewriting the code generator, and that the register allocation was based on the principle of always keeping three free registers between building blocks, which was inflexible and difficult to maintain.

For these reasons, the 1.1.''x'' series [[Branching (software)|branched]] off from the 1.0.''x'' main branch in December 1999. At first, changes were mostly clean-ups and rewrite-redesigns to all parts of the compiler. The code generator and register allocator were also rewritten. Any remaining missing Delphi compatibility was added.

The work on 1.1.x continued slowly but steadily. In late 2003, a working [[PowerPC]] port became available, followed by an [[ARM architecture|ARM]] port in summer 2004, a [[SPARC]] port in fall 2004, and an [[x86-64]]-AMD64 port in early 2004, which made the compiler available for a 64-bit platform.

In November 2003, a first [[Beta testing|beta]] release of the 1.1.''x'' branch was packaged and numbered 1.9.0. These were quickly followed by versions 1.9.2 and 1.9.4; the latter introduced OS X support. The work continued with version 1.9.6 (January 2005), 1.9.8 (late February 2005), 2.0.0 (May 2005), 2.0.2 (December 2005), and 2.0.4 (August 2006).

=== Version 2.2.x ===
In 2006, some of the major reworks planned for 2.2, such as the rewrite of the unit system, had still not begun, and it was decided to instead start stabilizing the already implemented features.

Some of the motives for this [[plan|roadmap]] change were the needs of the Lazarus integrated development environment project, particularly the internal linker, support for [[Win64]], [[Windows CE]], and OS X on [[x86]], and related features like [[DWARF]]. After betas 2.1.2 and 2.1.4, version 2.2.0 was released in September 2007, followed by version 2.2.2 in August 2008 and version 2.2.4 in March 2009.

The 2.2.''x'' series vastly improved support for the [[ActiveX]] and [[Component Object Model]] (COM) [[Interface (computer science)|interface]], and [[Object Linking and Embedding]] (OLE), though bugs were still being found. The delegation to interface using the <code>implements</code> keyword was partly implemented, but was not complete {{As of|2011|3|lc=on}}.<ref>[http://bugs.freepascal.org/view.php?id=8951 bugs.freepascal.org]</ref> Library support for ActiveX was also improved.

Another major feature was the internal linker for Win32, Win64, and Windows CE, which greatly improved linking time and memory use, and make the compile-link-run cycle in Lazarus much faster. The efficiency for smart-linking, or [[dead code elimination]], was also improved.

Minor new features included improved DWARF (2/3) debug format support, and optimizations such as [[Tail call|tail recursion]], omission of unneeded [[stack frame]]s and register-based [[common subexpression elimination]] (CSE) optimization. A first implementation of [[generic programming]] (generics) support also became available, but only experimentally.

=== Version 2.4.x ===
The 2.4.x release series had a less clear set of goals than earlier releases. The unit system rewrite was postponed again, and the branch that became 2.4 was created to keep risky commits from 2.2 to stabilize it. Mostly these risky commits were more involved improvements to the new platforms, Mac PowerPC 64, Mac x86-64, iPhone, and many fixes to the ARM and x86-64 architectures in general, as well as DWARF.

Other compiler improvements included [[whole program optimization]] (WPO) and [[devirtualization]] and ARM [[embedded-application binary interface]] (EABI) support.

Later, during the 2.2 cycle, a more [[Delphi (software)|Delphi]]-like resource support (based on special sections in the binary instead of Pascal constants) was added. This feature, direly needed by Lazarus, became the main highlight of the branch.

Other more minor additions were a [[memory management|memory manager]] that improved [[Dynamic memory allocation|heap]] manager performance in [[Thread (computer science)|threaded]] environments, small improvements in Delphi compatibility such as <code>OleVariant</code>, and improvements in [[Interface (computer science)|interface]] [[Delegation (programming)|delegation]].

On January 1, 2010, Free Pascal 2.4.0 was released, followed on November 13, 2010, by bug fix release 2.4.2, with support for <code>for..in</code> loops, <code>sealed</code> and <code>abstract</code> classes, and other changes.<ref>[http://wiki.freepascal.org/User_Changes_2.4.2 User Changes 2.4.2]</ref>

=== Version 2.6.x ===
In January 2012, Free Pascal 2.6 was released. This first version from the 2.6 release series also supported [[Objective Pascal]] on OS X and [[iOS]] targets and implemented many small improvements and bug fixes. In February 2013, FPC 2.6.2 was released. It contained [[NetBSD]] and [[OpenBSD]] releases for the first time since 1.0.10, based on fresh ports. In March 2014, the last point release in the 2.6 series, 2.6.4, was launched, featuring mostly database (fcl-db) updates.

=== Version 3.0.x ===
Version 3.0.0 was released on November 25, 2015, and was the first major release since January 1, 2012.
It introduced many new language features.<ref>{{Cite web |title=FPC New Features 3.0.0 |author= |website=Free Pascal wiki |date= |access-date=28 February 2021 |url= https://wiki.freepascal.org/FPC_New_Features_3.0.0}}</ref>

Version 3.0.2 was released on February 15, 2017, and includes bug fixes and minor compiler updates.<br />
Version 3.0.4 was released on November 28, 2017.<br /> 
It includes many language improvements over previous versions, including an internal linker for [[Executable and Linkable Format]] (ELF), Arm AARCH64 for iOS and Linux, a revived i8086 platform, extended libraries and much more.

=== Version 3.2.x ===
The next major release, version 3.2.0, was published on June 19, 2020. It introduced many new language features, including generic routines, standard namespaces, managed records and expanded functionality for dynamic arrays, in addition to the advent of new standard units and the support of additional platforms.<ref>{{cite web |title=FPC New Features 3.2.0 - Free Pascal wiki |url=https://wiki.freepascal.org/FPC_New_Features_3.2.0 |website=wiki.freepascal.org|access-date=2020-06-20}}</ref>

Version 3.2.2 was released on May 20, 2021, and supports macOS on [[Apple M1|AArch64]] and naming of threads. Additionally it includes bug fixes and minor compiler updates.<ref>{{cite web |title=FPC New Features 3.2.2 - Free Pascal wiki |url=https://wiki.freepascal.org/FPC_New_Features_3.2.2 |website=wiki.freepascal.org|access-date=2021-12-30}}</ref>