CompassCAD

very good architectural CAD software.

whether you are a beginner in CAD, or an experienced person in the industry, CompassCAD is for you.

features:
- 2D-only CAD design, great for sketching plans
- non-cluttered, simple and easy to use interface
- very light project file, sending your .ccad files over the air will be easy
- collaborate with up to 2 people (>1.6.1)
- lightweight and very low barrier of entry

note: CompassCAD is not CAD for machinery work nor is a parametric modelling software. do not expect everything to scale :)