It needed some time to port XCA to QT4. This enables me to use a modern API and take advantage of the free Windows port of QT4 for free software.
A lot of new features were added, like v3 extensions for requests or the more convenient input dialogs for issuer-alternative-name and others.
The Cetificate-wizard got replace by a tab-dialog to enhance the usability. The switch to OpenSSL 0.9.8 enables the newer hashing algos SHA256 and SHA512. The storage type of the asymmetric keys (DSA is supported now, too) was changed. The private key remains encrypted in the db and is only decrypted on demand. The keys also may get protected by different passwords.
The database format has changed completely.
This implies that older databases can not be easily used with 0.6.0 since it is not based on Berkeley DB anymore.
However, the old database may be dumped into an ASCII format with the Berkeley DB tool "db_dump".
XCA 0.6.0 is able to load the data from that dump file. More information in the docs.