Releases: tcltk/tcl
Tcl 9.0.3
Note
This is only part of the full release set of files, which can be found on SourceForge.
Tcl 9.0.3 Release Announcement
November 13, 2025
The Tcl Core Team is pleased to announce the release of Tcl 9.0.3. This is the third patch of Tcl 9.0.
Tcl is the Tool Command Language originated by John Ousterhout and his team at U.C. Berkeley in the late 1980s. Its development is continued by the efforts of a global network of volunteers guided by the Tcl Core Team.
We would like to express our gratitude to all those who submit bug reports and patches. This information is invaluable in enabling us to identify and eliminate problems. Such reports can be submitted here.
We ask that you log in (anonymous if you wish) to create tickets. This deters abuse of the ticketing system:
Where to get the new releases
Tcl 9.0.3 sources are freely available as open source from the Tcl SourceForge project's file distribution area:
The Tcl 9.0.3 distribution is source code only. We keep links to some third parties offering pre-built binaries for various systems here:
Tcl Summary
The Tcl distribution delivers C source code that builds into a C library providing interpreters and related supports to execute programs written in the Tcl programming language. Source code for the application program tclsh is also included. tclsh provides a shell for either interactive execution of Tcl commands, or execution of files containing Tcl programs.
Tcl is an extensible language, and the Tcl C library provides interfaces for the creation of extension libraries adding new commands and features to the core Tcl command set. Tcl 9 debuts the full feature set needed to package an application written in C and Tcl into a single file executable exploiting virtual filesystem archives.
Tcl Improvement Proposals (TIPs)
Each new user-visible feature in Tcl should find its origins in a Tcl Improvement Proposal (TIP). TIPs are published, edited, considered and voted in public, and should contain valuable information about how a feature came to be the way it is. See the full collection here:
Tcl 9.0.3 Changes Summary
(from changes.md in the source code distribution)
The source code for Tcl is managed by fossil. Tcl developers coordinate all changes to the Tcl source code at
Release Tcl 9.0.3 arises from the check-in with tag core-9-0-3.
Tcl patch releases have the primary purpose of delivering bug fixes to the userbase.
Bug fixes
- On Unix, IsTimeNative() always defined but not always used
- Tweak install permissions
- interp creation resets encoding directory search path
- Pointer arithmetic with NULL in buildInfoObjCmd()
- TclPushVarName(): pointer overflow
- Add IWYU export pragma annotations
- Windows: Install man pages
- Windows: Install pkgconfig
- Non-existent variables are ignored if re is {}
- bug in single-argument 'max' with bignums
Updated bundled packages, libraries, standards, data
- Itcl 4.3.5
- http 2.10.1
- opt 0.4.10
- platform 1.1.0
- sqlite3 3.51.0
- tcltest 2.5.10
- Thread 3.0.4
- TDBC* 1.1.13
- dde 1.4.6
- Unicode 17.0.0
Known bugs
- changed behaviour wrt command names, namespaces and resolution
- windows dos device paths inconsistencies and missing functionality
- load library (dll) from zipfs-library causes a leak in temporary folder
- lsearch -sorted -inline -subindices incorrect result
- "No error" when load fails due to a missing secondary DLL
For additional information:
Please visit the Tcl Developer Xchange web site:
This site contains a variety of information about Tcl/Tk in general, the core Tcl and Tk distributions, Tcl development tools, and much more.
Tcl Core Team and Maintainers
Jan Nijtmans, (replacement) Tcl Core Release Manager
Tcl 9.1a0
Note
This is only part of the full release, which can be found on SourceForge.
Tcl 9.1a0 Release Announcement
July 30, 2025
The Tcl Core Team is pleased to announce the release of Tcl 9.1a0. This is the first alpha release of Tcl 9.1.
Tcl is the Tool Command Language originated by John Ousterhout and his team at U.C. Berkeley in the late 1980s. Its development is continued by the efforts of a global network of volunteers guided by the Tcl Core Team.
We would like to express our gratitude to all those who submit bug reports and patches. This information is invaluable in enabling us to identify and eliminate problems. Such reports can be submitted here.
We ask that you log in (anonymous if you wish) to create tickets. This deters abuse of the ticketing system:
Where to get the new releases
Tcl 9.1a0 sources are freely available as open source from the Tcl SourceForge project's file distribution area:
The Tcl 9.1a0 distribution is source code only. We keep links to some third parties offering pre-built binaries for various systems here:
Tcl Summary
The Tcl distribution delivers C source code that builds into a C library providing interpreters and related supports to execute programs written in the Tcl programming language. Source code for the application program tclsh is also included. tclsh provides a shell for either interactive execution of Tcl commands, or execution of files containing Tcl programs.
Tcl is an extensible language, and the Tcl C library provides interfaces for the creation of extension libraries adding new commands and features to the core Tcl command set. Tcl 9 debuts the full feature set needed to package an application written in C and Tcl into a single file executable exploiting virtual filesystem archives.
Tcl 9.1 Release Summary
This is a new minor version of Tcl 9. When compared with the prior release Tcl 9.0, there are new features and interfaces. Tcl 9.1 should remain compatible with scripts and packages written to the public interfaces of Tcl 9.0. A summary of the most noteworthy changes is found below.
Tcl Improvement Proposals (TIPs)
Each new user-visible feature in Tcl should find its origins in a Tcl Improvement Proposal (TIP). TIPs are published, edited, considered and voted in public, and should contain valuable information about how a feature came to be the way it is. See the full collection here:
Tcl Changes Summary
(from changes.md in the source code distribution)
The source code for Tcl is managed by fossil. Tcl developers coordinate all changes to the Tcl source code at
Release Tcl 9.1a0 arises from the check-in with tag core-9-1-a0.
Highlighted differences between Tcl 9.1 and Tcl 9.0 are summarized below, with focus on changes important to programmers using the Tcl library and writing Tcl scripts.
New commands and options
New public C API
- Tcl_IsEmpty checks if the string representation of a value would be the empty string
- Tcl_GetEncodingNameForUser returns name of encoding from user settings
- Tcl_AttemptCreateHashEntry - version of Tcl_CreateHashEntry that returns NULL instead of panic'ing on memory allocation errors
- Tcl_ListObjRange, Tcl_ListObjRepeat, Tcl_TclListObjReverse - C API for new list operations
Performance
- Memory efficient internal representations for list operations on large lists.
Bug fixes
For additional information:
Please visit the Tcl Developer Xchange web site:
This site contains a variety of information about Tcl/Tk in general, the core Tcl and Tk distributions, Tcl development tools, and much more.
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Tcl Core Team and Maintainers
Don Porter, Tcl Core Release Manager