Software tools primarily for model engine machinists, but some may be useful for more general machine operations. See modelenginemaker.com as a popular site for such machinists.

Catalog of Gridfinity Designs and Other Resources

Sligtly modified version of gridfinity storage system, modelled in freecad

Openscad Bitbeam library

Bitbeam = Lego + Grid Beam = Awesome

Imprimible pcbs

Arduino code. Eagle schematic and board files.

dfu-programmer is a Device Firmware Update based USB programmer for Atmel chips with a USB bootloader

Inverse kinematics control library for Phenoptix meArm

Laser cut files for MeArm