What are some alternatives?
When comparing Etabs and MASTAN2, you can also consider the following products
RISA-3D - Structural Analysis and Design
Estru3D - SourceForge presents the Estru3D project. Estru3D is an open source application.
SAP2000 - The SAP name has been synonymous with state-of-the-art analytical methods since its introduction...
Structurix - Analysis of structures based on the principle of the finite element method.
RISA-2D - Structural Analysis and Design
midas Civil - Structural Analysis and Design