Unum stands for 'unit-numbers'. It is a Python module that allows defining and manipulating true quantities, i.e. numbers with units like volts, hours, meter-per-second. Consistency between units is checked for every operation involving quantities.
Geotag Merge is designed to combine track data from a GPS unit with EXIF data in a series of photographs. A handheld GPS can be simply carried while taking photos, and the photos can later be automatically gettagged (by matching timestamps).