OpenSCAD is an open source programmatic CAD program. If you're a programmer OpenSCAD will be very familiar.
Ranked in these QuestionsQuestion Ranking
Pro Text based description
Hence the resulting files can be easily stored/merged in version control systems.
Pro Ideal for programmers
Because the 3D-objects will be programmed. You define basic geometric objects, scale, rotate or move them, create unions, intersections, hulls, differences, ...
Define some variables and use them in the code.
Pro Easy to use
Con SVG exports a single big shape
It should export one shape per object, so it would be re-usable in SVG tools.