Tcl/Tk 9.1

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. 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: select items from list New command interp set: variable access in child interpreter New subst options: -backslashes, -commands, -variables. New switch options: -integer. Many C99 math routines now available as expr functions. Applications now required to call an initialization routine, either Tcl_FindExecutable or TclZipfs_AppHook. New C routine Tcl_IsEmpty. New C routine Tcl_GetEncodingNameForUser. New C routine Tcl_AttemptCreateHashEntry. New C routines Tcl_ListObjRange, Tcl_ListObjRepeat, Tcl_ListObjReverse. New C time API using long long in place of Tcl_Time Case-insensitive filesystem paths on macOS. auto_execok and exec search reform on Windows. Revised searches for script library and encodings. Improved list internals for memory efficiency of large lists. Extended support for 64-bit sizes. Highlights of Tk 9.1 Accessibility screen reader support. Initial support for bidirectional text / RTL languages. New widget ttk::toggleswitch. New command tk attribtable. send command revised and improved on Aqua. Handling of negative screen distances. Extended states in ttk::treeview and ttk::notebook Improvements to Tk_CanvasTextInfo Rotated text on labels Limit message box and dialogs to physical screen width. Improved listbox selection colors. Removed obsolete support for Windows XP appearances. This is the main Tcl Developer Xchange site, www.tcl-lang.org . About this Site | [email protected] Home | About Tcl/Tk | Software | Core Development | Community | Documentation