heekscad what can be done to make it part of the apt repository and be improved?

>heekscad what can be done to make it part of the apt repository
Well you would need to build a "deb" package, get it loaded into the upstream Debian repository (the ubuntu developers do a mass copy of the debian repository every few months ("debian import")).

This requires knowledge of programming, linux filesystem layout (what is /etc/ /usr/ /bin/ /lib) and the language that the developer has chosen to use, as well as using version control (eg git/mercurial/subversion).

The instructions for getting a package together are here:
http://www.debian.org/doc/maint-guide/
Slightly less steep guides can be found by searching, and there are innumerable video tutorials

Its very much a sink-or-swim situation however, and a black art. A CAD program is probably not the easiest choice for a first package; particularly if it relies on complex components such as OpenCASCADE. The best thing to do is to try to take an existing package, see if you can make a small change in it, then rebuild it and install it on your system. There are some guides on how to do this, and it is much easier than building one from scratch.

However, it appears that you are in a bit of luck, someone has already put in a "please can some nice person package this" request for debian here: http://bugs.debian.org/560766 . Looking there, Bdale Garbee said he would work on it, so maybe you can send him an email (it is listed on that page), and have a chat there.

I forgot about the other half of your question.

You could download heekscad' s source, rebuild it from its source code, and then decide what bugs need to be fixed, then fix them.

If you are unable to program, sometimes projects can benefit from simple things like translation (if you know a non-english language), or by writing documentation or creating tutorials.

The source code is available via the version control system "subversion" so you can grab it and just start editing stuff.

svn checkout http://heekscad.googlecode.com/svn/trunk/ heekscad-read-only

it might be an idea to offer to help the developer by sending him an email directly.

Decide what skills you have, what skills you can attain, and how these might be useful to the project -- I am certain that the assistance will be greatly appreciated by the developer.