In the non-starkit TclHttpd distribution, there is also the much faster binary version packaged as 'crypt'.
These are also available separately here: http://vectorstream.com/tcl/packages/
The trf package also provides the crypt function, but apparently not on the Windows platform at least.
While on the general subject - beware that at least one crypt implementation (crypt.exe in Cygwin on Windows) takes its 'password & salt' arguments in the reverse order to that of the Tcl implementations mentioned above.
See md5crypt for a more 'modern' method of password encryption.