The short answer to your question is NO. Clipper RDDs are not functional with Alaska Xbase++. Xbase++ does have an inovative modular driver engine though. It has compatibility drivers for a variety of Clipper, Foxbase, FoxPro, and dBase DBF, memo file, and index types. But none that I have seen for Btrieve.
Having said that - I am among those who have jumped on the Alaska Xbase++ bandwagon totally. I found that 99% of my code worked with only a single line or two added to invoke the mouse, etc. Only where I strayed from pure Clipper and used 3rd party tools did I run into any difficulty. I have worked around most of those, and am honing my object oriented coding skills in order to make use of some ActiveX libraries that will fill the remaining needs.
If you are comfortable with Clipper syntax - you will adapt to Xbase++ easily. There are numerous new features primarily oriented toward building GUI user interfaces - but the nice thing is you can convert existing Clipper apps with minimal work. They will still "look like" DOS apps - although in reality they will be true 32bit apps. Rewriting to get to a GUI environment can be done later as your skill and knowledge grow.
We bought Alaska Xbase++, Xpress++ (useful for compatbility with Clipper (REPORT FORM for example), JazzAge (allows easy use of ActiveX and OCX libraries from VB or C++, etc.) and TopDown Library - another neat library that makes the transition from DOS to GUI a little bit friendlier.
To the best of my knowledge, it won't do Btrieve - but it will do most other Clipper things quite handily.
John
