Free Software
Mobile Atlas Creator
Mobile Atlas Creator is a free and open-source software which can create atlases for GPS handhelds and mobile applications like TrekBuddy. Individual maps can also be exported as large PNG files with MAP file calibration for OziExplorer. Mobile Atlas Creator also integrates well with third-party online maps providers sush as OpenStreetMap.
LXLE
LXLE is a free and open-source Linux distribution based upon the most recent Ubuntu/Lubuntu LTS release, using the LXDE desktop environment. LXLE is a lightweight distro, with a focus on visual aesthetics, that aims to support most of both old and new hardware.
Apache Accumulo
Slic3r
With Slic3r, you can slice 3D objects and create G-code files ready for production 3D printing of physical object. It's a free and open-source 3D slicing software released under the AGPLv3 license. Slic3r is used by professionals and hobbyists alike and anyone is free to contribute to its source code. All development of the Slic3r software happens in their GitHub repository, and discussion around the software happens on the #slic3r IRC channel on FreeNode.