Latest Release: Tcl/Tk 9.1.0 (Sep 29, 2026)
Tcl/Tk 9.1.0 is the current betterment activity on Tcl and Tk, aiming toward stable releases in September 2026. They add new features and interfaces to the basis of Tcl/Tk 9.0.
Download Tcl/Tk 9.1.0 Source Releases
Highlights of Tcl 9.1
- New command unicode: Unicode normalization
- New C routines Tcl_UtfToNormalized*: Unicode normalization
- New command timer: monotonic clock; microsecond resolution
- New command lfilter: choose items from list
- New command interp set: changeable admission in kid interpreter
- New subst options: -backslashes, -commands, -variables.
- New switch options: -integer.
- Many C99 math routines now accessible as expr functions.
- Applications now required to call an initialization routine, either Tcl_FindExecutable or TclZipfs_AppHook.
- New C regular Tcl_IsEmpty.
- New C regular Tcl_GetEncodingNameForUser.
- New C regular Tcl_AttemptCreateHashEntry.
- New C routines Tcl_ListObjRange, Tcl_ListObjRepeat, Tcl_ListObjReverse.
- New C period API using long long in location of Tcl_Time
- Case-insensitive filesystem paths on macOS.
- auto_execok and exec hunt improvement on Windows.
- Revised searches for manuscript archive and encodings.
- Improved catalog internals for recollection effectiveness of ample lists.
- Extended assistance for 64-bit sizes.
Highlights of Tk 9.1
- Accessibility display audience support.
- Initial assistance for bidirectional content / RTL languages.
- New widget ttk::toggleswitch.
- New command tk attribtable.
- send command revised and improved on Aqua.
- Handling of negative display distances.
- Extended states in ttk::treeview and ttk::notebook
- Improvements to Tk_CanvasTextInfo
- Rotated content on labels
- Limit communication box and dialogs to bodily display width.
- Improved listbox choice colors.
- Removed obsolete assistance for Windows XP appearances.
