With what other PGP software is OpenPGPBlackbox compatible?
OpenPGPBlackbox package of SecureBlackbox is implemented according to RFC 2440 and 4880 which define OpenPGP standard. OpenPGPBlackbox is compatible with any software that follows this standard.
When it comes to PGP Software products, generally the files generated by this software are processed without problems. Theoretically PGP Software can use proprietary patented extensions like split keys etc., but since release of OpenPGPBlackbox in '2005 we never ever come across such file.
Now the tricky part. PGP (software) came in different versions most widespread of which are 2.6.3, 5.6 and 8.x / 9.x. Each of those versions has it's own shortcomings, specifics and deviations from the standard. Eg. version 2.6.3 uses IDEA (patented algorithm) and RSA keys. Version 5.6 uses CAST and can work with ElGamal and RSA keys, but has some other shortcomings. Now, versions 2.6, 5.6 and 8/9 use different formats of packets and some other options. OpenPGPBlackbox deals with all of described complexities.
OpenPGPBlackbox supports processing of multiple files stored in one PGP file (this is the new feature of PGP Desktop 9.x) and also supports creation of such files.
Various versions of GnuPG etc. are supported as long as these applications follow the above mentioned standards.