Tcl/Tk 9.0 released with 64-bit compatbility, Unicode and SVG support, and much more

The most recent major release of the Tcl language and graphical-user-interface toolkit, Tcl/Tk 9.0, has been released, marking a significant update 27 years after the 8.0 major release in 1997. Tcl 9.0 introduces 64-bit compatibility, enabling it to address data values larger than 2 GB, alongside enhanced Unicode support, the ability to mount ZIP files as file systems, new UNIX notifiers, and a host of new commands and features.

Tk 9.0 also sees substantial improvements, including support for scalable vector graphics and better platform integration, such as system trays and gestures. However, this new release presents some incompatibilities with Tcl/Tk 8. While many Tcl programs written for Tcl 8 will run unchanged in Tcl 9, others may require minor modifications to be compatible with both versions. Extensions and applications using the public Tcl C APIs will need more effort to support both Tcl 8 and Tcl 9.

It is important to note that Tk 9.0 does not support Tcl 8.6. As new Tk features are developed, they are expected to appear in Tk 9, but not necessarily in Tk 8.6.