Calculator: TEDDS by CSC (works within MS WORD 2000, 97, NT)
Struct. analysis: Multiframe4D by Formation Design (very easy modeling capability, graphic interface for modeling and loads, very easy to select and combine load cases, automatic generation of dead loads, includes non-linear and time-history analysis)
CAD Drafting: Visual CADD 4.0 (very fast and easy to use - learning curve is about 2 weeks) - A little history on Visual CADD: The DOS version was Generic CADD which company was purchased by Autodesk ~1992. Autodesk (developers of AutoCAD) promised to support and develop the product to run under Windows for much wider distribution (at the time Generic CADD had over 200,000 users). This simply didn't happen -- Autodesk ended up killing the software and no longer distributes Generic CADD (said conversion to Windows was not possible). The developers of Generic CADD left Autodesk ~1995 and resurfaced with the product name Visual CADD. The product runs under Windows and runs circles around AutoCAD in learning curve, ease of use, and flat-out drawing speed. The product is only 2D at this time, but expect to see a 3D version sometime soon. This is an EXTREMELY user-friendly product whose popularity should grow as the word spreads.
Have other products, but these are my favorites.