Command: package package forgetpackage}
Remove all info about package from interpreter.
package ifneededpackageversion [script]}
Tells interpreter that if version version of package,
evaluating script will provide it.
Returns list of all packages in the interpreter that are
currently provided or have an ifneeded
package providepackage [version]}
Tells interpreter that packageversion is now provided.
Without version, the currently provided version of package is returned.
[-exact] package [version]}
Tells interpreter that package must be provided. Only
packages with versions equal to or later than version
(if provided) are acceptable. If -exact is specified,
the exact version specified must be provided.
Specifies a last resort Tcl command to provide a package which
have append as its final two arguments the desired package and version.
Returns -1 if version1 is earlier than version2, 0
if equal, and 1 if later.
Returns list of all versions numbers of package with an
Returns 1 if version2 scripts will work unchanged under version1.