See the SourceForge downloads page. There are four different files available for the latest release:
PortaBase_2.1.dmg- Mac OS X disk image; should work on 10.5 and up, 64-bit Intel only. If anybody still wants a PowerPC or 32-bit Intel version, let me know and I can make one available.
portabase_2.1-1_i386.deb- Installation package for Debian GNU/Linux (unstable branch, 32-bit x86 processors).
PortaBase_2.1.exe- Windows installer; should work on 2000, XP, Vista, and 7.
portabase_2.1.tar.gz- Source code tarball, contains instructions for building on all supported platforms.
Maemo users should get PortaBase from the appropriate repository; as of this writing, version 2.1 is available from extras-devel in both Diablo and Fremantle (version 2.0 is already in extras).
Debian users can install a post-2.0 git snapshot from the unstable distribution, 2.1 should become available in time.
Pandora handheld PC users can download a binary of version 2.0 here.
Known issues with the latest release are listed here.
I'm sorry to disappoint Zaurus users, but there won't be any further releases of PortaBase for the Zaurus. I did attempt a code base that could span the library versions available on the Zaurus and more modern systems, but the result wasn't very pretty and was just too much work for a one-man hobby project (in fact, it discouraged me from working further on PortaBase for a few years). With PortaBase now working on the Nokia N810 and N900, I've switched over to using those as my pocket computing devices. The file format hasn't changed at all for PortaBase 2.0 or 2.1, so files can be moved freely between 1.9 on the Zaurus and 2.1 elsewhere.
As a reminder, the Zaurus files available for 1.9 are:
portabase_1.9_new_sharp_roms.zip- Zip file containing the Zaurus installation package for ROMs which have the Sharp library containing the improved file navigation widget (SL-5500 with the 3.10 ROM, SL-5600 with a Sharp ROM, any of the Japanese Linux Zaurus models running a standard ROM, etc.)
portabase_1.9_other_roms.zip- Zip file containing the Zaurus installation package for all other ROMs (SL-5000D, older SL-5500 ROMs, OpenZaurus, etc.) This can also be used on the newer Sharp ROMs, but will use the old-style file selection list instead of the directory browsing file navigator (less flexible and slower, especially if you're using large CF and/or SD cards).
Developers who want to build PortaBase for themselves from the latest development code can get it from the git repository. Instructions on how to build PortaBase for various platforms can be found in the INSTALL file in the root directory. This has actually gotten much easier since PortaBase 1.9 thanks to the creation of an assortment of build scripts.