The Tcl Core

The Tcl core is the C implementation of Tcl. It is managed and maintained by the Tcl Core Team.

See Also

Getting Started With Working On The Tcl/Tk Core
Hacking on The Core
Tips, Tools, Techniques.
Quality of source code
Tcl Core - Is All
Tcl Core Architecture
tcl core subsystems
Category Internals
An automated index of pages categorized as related to the Tcl internals.
Tcl Functional Areas
An overview on the Tcl Core wiki of the functional areas of Tcl.
Tcl Core Wiki Contents
a list of pages on that wiki.

Resources (alternatively core and )
Official fossil source code repository and issue tracker.
Github mirror of Tcl/Tk and related code.
Current single-file binary builds: Tcl 8.7 , Tcl 9.0 , Tk 8.7 (github login required for download; note that macOS builds are unsigned; see the included README.txt for how to use the binary)
Previous project site for the development of Tcl. Although the old source code repository, mailing lists, and bug tracker remain there for historical purposes, they are no longer updated.


Previously, development code was hosted in a CVS repository at


An allocator that returns memory to the system and attempts to remain free of lock contention.

What Links Here

Fetching backrefs...