Originally posted by Doctor Q
In answer to the "what is this stuff" part of your question, it is the program you are trying to download. The problem is that your web browser is displaying the content instead of saving it to a disk file. The content of a program is a binary file, and trying to interpret it as text produces all the funny characters.
I think the problem occurs because versiontracker (or, in general any web server) is returning the wrong Content-Type (also called MIME type) in the HTTP header. The web server is saying "here comes your file, which is of type text/plain", when it should have said "here comes your file, which is of type application/octet-stream" (or some other non-displayable data format).