Since October 2010, Tcl 8.6 has had IPv6 [socket] support built in.

[Ceptcl] provides IPv6 among other protocols.  Windows users might be interested in [iocpsock].

[Jim] Tcl has had IPv6 '''and''' UDP support since Oct 2010.

[tcllib_ip] has (incomplete) support for parsing and manipulating IPv6 addresses.

Old (ca 2010, ~8.0, 8.3) Unix implementations might be able to use this patch:  http://www.unnumbered.net/~umeno/etc/tclIPv6patch.htmkkl

See:

  * [IPv6 Addresses] - a tiny module for parsing and formatting
  * [A Little 6to4 Calculator]


This
[http://groups.google.com/group/comp.lang.tcl/browse_thread/thread/130148cef9ebd956]
thread hints at a couple of the challenges in getting Tcl's high-level socket programming
interface right.

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[Stu] 2009-06-17 I noticed that [Ceptcl] wasn't mentioned in that thread, I wonder why.
I'd post this to the thread itself but my 'net conn's sporadic lately.
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