TAD (The Architect's Desktop) is now available free !
It would be nice if you can contribute some amount into this project using the above link. ₹ 1000.00 is approx $15.00 USD
It is a very easy, space based BIM (Building Information Modeler) software for architects all over the world.
Getting your own copy of TAD is as easy as getting a free registration at a chatting system for TAD here https://goo.gl/rRspC8 and then follow the instructions here: https://goo.gl/UgW0Ub , to download and install your free copy.
Quite a lot of documentation is here https://goo.gl/9V6Rcm
Currently, the freeware (non-open source) version of TAD is the 6.x series. Simultaneously, the 7.x versions of TAD is also being started using new code that works inside browsers, using the open-source development route. And of course, that too would be free.
Read this appeal from the author, Sabu Francis: https://goo.gl/VA4w97
Note: International donors cannot currently use this payment system. Please write to firstname.lastname@example.org and we'll supply the bank transfer details