Dear Ashley :
Note that RiverCAD 2000 can open and save AutoCAD DWG and DXF files, from version 14 and earlier.
RiverCAD XP, which operates in AutoCAD 2000 through 2008 can open AutoCAD DWG and DXF files.
RiverCAD ProSA, which is about to be released, is built on top of AutoCAD 2008 OEM and can open and save AutoCAD DWG and DXF files up through version 2008, and can also open and save Microstation DGN files.
Please let me know if you need further assistance.
Sincerely,
Chris E. Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com