Tcl/Tk 9.1 Released
Tcl/Tk 9.1.0 has been released, introducing several new features including Unicode normalization, a monotonic clock, and improved list internals. The update also includes various C routine enhancements and platform-specific improvements for macOS and Windows.
Why it matters
This release represents a significant step in the ongoing development of the Tcl/Tk language, providing developers with better performance and modern interface capabilities.
Latest Release: Tcl/Tk 9.1.0 (Sep 29, 2026)
Tcl/Tk 9.1.0 is the current development work on Tcl and Tk, aiming toward stable releases in September 2026. They add new features and interfaces to the foundation of Tcl/Tk 9.0.
New command unicode : Unicode normalization
New C routines Tcl_UtfToNormalized* : Unicode normalization
New command timer : monotonic clock; microsecond resolution
New command lfilter : select items from list
New command interp set : variable access in child interpreter
New subst options: -backslashes , -commands , -variables .
Many C99 math routines now available as expr functions.
Applications now required to call an initialization routine,
either Tcl_FindExecutable or TclZipfs_AppHook .
Get smarter about the news
Sign up free for a feed built around what you actually care about, Dive Deeper research on any story, and the full text of every article.
Create free accountAlready have an account? Sign in