Not really. Both are unneeded extensions on Unix, that drive me and many other experts nuts. You don't call cat as cat.c! A user should not need to know the implementation language to invoke a program.

Additionally, when used as part of a URL, they give away the implementation language to random users out on the net--a major security hole.

So if your webserver or O/S needs an "extension" to determine that it's a CGI script or a Perl script, please don't use it for anything other than a toy. Real web servers don't need or use those.