There are a number of decent download extensions for Joomla but none of them match the functionality of DOCman. Unfortunately, it isn't one of the nicer looking extensions with it's default theme and developing new themes for it is an arduous task so there aren't many available.
Many of the newer download/file management extensions like RubberDoc and RokDownloads are styled quite nicely but lack some of the robustness that DOCman offers. Remository is the closest to DOCman but has it's quirks too and doesn't provide much more in terms of default styling.
For the JoomlaFare site, we decided to take a stab at developing a DOCman theme styled after the RokDownloads component from RocketWerx. As with all of our extensions, we're pleased to offer this freely to the community, both in cost and under license (GPL).Please note: This is a Beta release that has only been tested on a limited number of OS/browser combinations. Also, this is not in any way endorsed by or associated with RocketWerx or Joomlatools.