A brief description of each implementation of Tcl listed in [Category Tcl Implementations], preceded by the language of its source code.

   * C, [Tcl] is the definitive implementation and is written in C.  The same code base can be used with different build options or targets, different sets of add-on packages, or different packaging (e.g. as a single binary file).  These variations are distributions of [Tcl] and are covered in [Category Distribution].
   * C, [TinyTcl] is a slimmed-down fork of Tcl 6.7
   * C, [ettcl] is a slimmed-down fork of Tcl 7.x
   * C, [PalmTcl] is a fork of Tcl 7.6 for PalmOS v3.x. See also [Small Tcl].
   * C, MicroTcl is a small subset of Tcl 8.4 for the Nebula 2 game/visualisation engine.  See [Small Tcl].
   * C, [Jim], intended as a small-footprint implementation of Tcl 8.x (not a fork of 7.x or earlier)
   * C, [Picol], a small interpreter in 500 lines of code - described as "an educational toy model only, it is weaker and slower that real Tcl"
   * C, [Capicol] [[please add description]]
   * C++, [TinyTcl] (same name, different project) is a small interpreter written from scratch
   * C#, [tclcsharp], a port of [Jacl] to [.NET]
   * C#, [Jacl.NET], another port of [Jacl] to [.NET]
   * Parrot, ParTcl is the Tcl implementation for [parrot], the Perl 6 virtual machine
   * Java, [Jacl], intended as a full implementation of Tcl in Java
   * Java, [Hecl], designed to be small, intended for J2ME cellphones
   * JavaScript, [Tcl in JavaScript], converted from [Picol]
   * FORTRAN, [FEMTOL]
   * ''concept'', [HereTcl], [MicroTcl for Tcl9], [The Very Minimal Tcl Core Command Set], [Titoo: a thought experiment] or T2, [Implement tcl in tcl]
   * Haskell, Hiccup [http://code.google.com/p/hiccup/], a proof of concept inspired by [Picol], aims to mostly match Tcl 8.5 features

Several of these implementations are intended to reduce the footprint of Tcl.  For a discussion of these small implementations, see [Small Tcl]. Many take advantage of the smaller size of earlier versions of (definitive) Tcl: see [Advantages and disadvantages of different Tcl versions] for a comparison.

Implementations of other languages that have recognisable similarities to Tcl:
   * tinker - see [TinyTcl]
   * Ficl [http://ficl.sourceforge.net/] is really an implementation of Forth
   * Cricket - see [Small Tcl]

Other systems listed on [Category Tcl Implementations] are not distinct implementations:
   * [Parenthetcl] is a Tcl/C hybrid for writing compiled Tcl extensions
   * [Tclkit] is really a [Tcl] distribution.  It is a single binary file that provides Tcl/Tk and a number of popular extensions.

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[Category Tcl Implementations]