Zyrill writes "The Germany based company Stuttgarter Struktur AG has released a free and open source implementation of the H.265 codec also termed "High Efficiency Video Coding (HEVC)" which is now available on Github. At the same video quality, H.265 promises roughly half the bitrate as compared to H.264. Also, resolutions up to 8K UHD (7680 × 4320 px) are supported. The software is licensed under LGPL.
Quoting from the homepage where the software is also available for download: "[This software] is written from scratch in plain C for simplicity and efficiency. Its simple API makes it easy to integrate it into other software. Currently, libde265 only decodes intra frames, inter-frame decoding is under construction. Encoding is planned to be added afterwards.""