I've just had a look at http://wiki.debian.org/DebianScience/cctbx. I think ssm (or libssm) is missing in the list of dependencies. The sources are at ftp://ftp.ccp4.ac.uk/opensource/ The packages there have dates appended to versions, because they are actually repository snapshot. I've setup OBS repository (to evaluate usefulness of OBS) with a few ccp4 libraries, only RPMs for now: https://build.opensuse.org/project/show?project=home:wojdyr:ccp4 It's a really nice service, user's interface looks like this (superpose is a small program, part of the ssm library): http://software.opensuse.org/download?project=home:wojdyr:ccp4&package=superpose I'd like to add also debian packages there, but I have less experience with debs, so I'll wait until you guys make packages for Debian and then I'll copy it. Regarding forked versions of mmdb and libccp4: Eugene actively maintains mmdb and fixes bugs from time to time, so it's better to take it directly from us. gpp4 is a fork of a subset of libccp4 (maybe it was forked before libccp4 was separated from the ccp4 codebase), but the difference is not big. libccp4 requires another additional dependency, ccif, but it can be avoided using --disable-ccif (ccif is not needed for cctbx and coot). AFAIK coot works fine with the latest versions of the libraries and the versions in cctbx are updated nightly from our repositories. And a question about so-versions: is it a formal requirement for Debian packages? What will be the initial so-version of cctbx? 0.0.0? Marcin