Pegamento is a hardware accelerated image compositing application. It's also a Spanish word, which means "glue", and that's indeed the purpose of the application: To glue things in a canvas.

The application is highly focused in hardware acceleration, not only for the interactive work, but also for (high-quality) final rendering. If you want a 100% software-based solution, this is not what you're looking for.

The current beta version is available free of charge, at the download section. Future versions might be released as commercial software, or might continue being free of charge software.