Today marks the 15th anniversary of the formal creation of Matroska. The project was created on Sourceforge on the 6th of December 2002.
Following discussions on our mailing list to better support the Opus codec, we added some elements to Matroska v4:
There are also internal changes made to prepare libebml2 and libmatroska2, our new C libraries for a future release. The libraries are now more modular and easier to integrate without the need for coremake.