# SWI-Prolog Versions

SWI-Prolog is distributed as platform specific binary package for
popular platforms (currently MS-Windows and MacOS X). For
[Ubuntu](http://www.ubuntu.com) Linux we provide a
[PPA](</build/PPA.html>).  For all Linux systems supporting snap we
provide the snap package [`swi-prolog`](</build/snap.html>).

The source package provides the GNU autoconf/make suite to configure and
build fully automatically on many platforms. It builds on a wide range
of 32 and 64 bit systems with an ANSI C compiler. The MS-Windows version
is built using [[MinGW][http://mingw.org/]] as a cross-compiler under
Linux. See the file README.mingw in the toplevel directory.

SWI-Prolog *stable* releases have an *even* minor version number
(8.0.x, 8.2.x, 8.4.x, ...) and *development* releases an *odd* minor
version number (8.1.x, 8.3.x, ...). The development versions are
released frequently, typically every couple of weeks). A new stable
cycle is started when the development version has improved enough to
make upgrading valuable for many users and large changes to the
development versions have proven to be stable. As of 7.4.x we plan to
provide regular stability and security fixes for the stable version and
we will avoid incompatible changes.

All sources are available on [GitHub](http://github.com/SWI-Prolog). The
repository [swipl.git](http://github.com/SWI-Prolog/swipl.git) is used for
the stable versions and the repository
[swipl-devel.git](http://github.com/SWI-Prolog/swipl-devel.git) for the
development series.  Releases are tagged *V*_|Major.Minor.Patch|_.

  $ 8.3.0: Current development series.

  $ 8.2.x: Brings advanced tabling support of XSB to SWI-Prolog: Well
  Founded Semantics, restraints, incremental tabling and shared tabling.
  It also makes rational numbers primary citizens. Using Google's
  tcmalloc reduces the memory footprint drastically on some
  multi-threaded workloads.

  $ 8.0.x: Indexing on multiple arguments together, indexing inside compounds,
  Mode-directed tabling, saved states using ZIP files, many deployment
  enhancements. Moved build environment to [CMake](https://cmake.org) and
  removed most of the build tool dependencies.  Builds documentation along
  with the binary.

  $ 7.6.x: Major release. Multi-argument indexing, better multi-threaded
  performance, threaded global GC (atoms and clauses), mode-directed
  tabling, restored same expand and directive semantics for initial load
  and reloading files, cleaner initialization and command line handling.

  $ 7.4.x: Major release.  More robust and better scalable support
  for multi-core hardware, tabling, engines.  Many enhancements to
  the RDF, HTTP and SSL libraries.  This is the first release licensed
  under the _Simplified BSD_ (BSD-2) license.

  $ 7.2.x: Major release, providing native key-value support by means
  of _dicts_, native _strings_ using "hello world" syntax,
  web-accessible Prolog engines (Pengines) and a high level SQL library
  called CQL. See [extensions](</pldoc/man?section=extensions>).

  $ 6.6.x: Mostly a stability release. 6.6.x comes with some
  modification, notably to processing commandline arguments. It has been
  stabilised rather quickly because the 7.1.x branch introduces many and
  partially incompatible changes.

  $ 6.4.x: RDF database version 3, quasi quotations, many enhancements to
  HTTP and HTML environment, many enhancements to the development tools,
  bug fixes.

  $ 6.2.x: The _pack_ package installer, better =|:- include(file).|=
  support, many enhancements to debugger and environment.  Windows version
  built using MinGW (about 20% faster then MSVC2005 version).

  $ 6.0.x: Stable branch created from 5.11.37.  Notably provides just-in-time
  indexing on multiple arguments and supports the PDT Eclipse IDE out of the
  box.

  $ 5.11.x: External requirements have forced the release of 5.10.x
  before the wishlist of new functionality was complete. Notably
  generational GC remains on the wishlist.

  $ 5.10.x: Stable branch with the achieved 5.9.x enhancements: better
  scalability in terms of memory usage and concurrency, better
  reliability and better compatibility.

  $ 5.8.x: Stable branch providing performance enhancements from 5.7.x,
  many extensions and enhancements to the libraries; notably the
  web and semantic web libraries.

  $ 5.6.x: Stable branch providing UNICODE handling, unbounded and
  rational arithmetic, enhanced Leuven CHR system, clp(q,r), clp(fd),
  much enhanced (semantic) web libraries, etc.

  $ 5.4.x: Stable branch providing attributed variables, coroutining,
  CHR (Constraint Handling Rules), infinite trees (cyclic terms) and
  many more. This is the last version that runs on Windows 95/98/ME.
  5.5.x and later require Windows NT, 2000 or XP.

  $ 5.2.0: Stable version providing multi-threading.

  $ 5.x.y: Moved to uniform LGPL license. Standard distribution contains
  core packages: XPCE (graphics), TCP/IP, CGI, SGML/XML/HTML/RDF, HTTP,
  ODBC and many more.

  $ 3.4.5: Version prior to integration. Compliant to the ISO Prolog
  standard (part1).

  $ 3.2.9: Last pre-ISO version. As 3.3.0 is not fully upward compatible
  this version will remain on this server for a while. It will not be
  maintained (by us)