We originally used to carry both statically and dynamically linked binaries for packages on the archive in order to provide wider platform support (e.g. we built the statically linked binaries with PA-RISC 1.0 flags, but the dynamically linked binaries were built with PA-RISC 1.1 flags) and also to eliminate the need for dependencies if so desired (in general, statically linked binaries had no dependencies on other packages in the archive).
However, those benefits were eventually outweighed by 1) the phasing out of PA-RISC 1.0 machines from HP's product line, 2) the increased complexity of the builds (because HP don't ship .sl versions of some .a libraries, this necessitated "spelling out" the full path [e.g. /usr/lib/libPW.a] to a library, rather than using the shorter variant [e.g. -lPW]), 3) the necessity of linking static binaries with /usr/lib/dld.sl (see the WARNINGS section of "man 3C iconv") and 4) the much greater size of the statically linked binaries compared to the dynamically linked binaries (resulting in excessive disk usage and, of course, much longer download times).
Hence, the decision was taken to eliminate all statically linked binaries from the archive and this has now been achieved. By freeing up a substanital amount of disk space, we were better prepared to host five binary platforms (now PA-RISC 11.11 and PA-RISC/Itanium 11.23/11.31) rather than just one. In case you're wondering why we didn't just buy bigger disks, remember that this means 3 * the extra disks of course (we have 3 official sites), so that isn't a viable solution.
Note that we are now listing the (usually shared library) run-time dependencies for dynamically linked packages on each package's Web page - you should transfer and install those run-time dependencies first prior to installing the dynamic binary package you originally wished to install.
If a package doesn't have any run-time dependencies, then this usually means that its binary depot can be transferred and installed without needing to obtain and install other binary depots first. Note that there are often additional build-time dependencies required if you are building the package from source code - those build-time dependencies are always a superset of the run-time dependencies and usually include further packages to be installed (particularly make).