The dev board contains boards that are restricted in 1 way or another. The 1.3 and 1.4 testing/bugs board should be visible to you, but only members of the testing group and above can post to these boards. The other boards on the devs board are visible to devs only.
Version 1.4 is still in alpha testing, and is open to testers only because we don't want to be inundated with incorrect bug reports or support requests from people not familiar with coppermine. But it is open to view so people who have decided to try it can see what is going on, see what bugs have been reported and fixed.
Anyone can get the latest files, from the cvs. Using a software like tortoise is recommended, but you can do it file by file via the html link.