Predicate is consisted of a C++ Qt-only library and set of plugins. Because there is no dependency on Kexi, Calligra or even on KDE libraries, Predicate is available for very wide audience. At some point Kexi will use it too, thus deprecating KexiDB.
Predicate is widely free/libre software available under the GNU Lesser General Public License (LGPL). Thus, developers are free to:
- use Predicate in applications
- extend it for specialized use cases
- contribute directly to Predicate
Read about history of the project in the KDE Commit-Digest.