- twitter.com brl_cad?lang=plBRL-CAD is a powerful cross-platform open source solid modeling system...
- vk.com wall-38200654_362BRL-CAD: Open Source Solid Modeling brlcad.org.
- BRL-CAD (brlcad.org) is the clear winner in the free category.
- hovulik.livejournal.com 387512.htmlhttp://www.opencascade.org/ http://brlcad.org/ http://en.wikipedia.org/wiki/Category:Free_computer-aided_design_software.