ThinLinc 4.13.0 has been released after nearly 8 months of development. According to the release notes the re are 120+ enhancements and fixes, but the big news is support for Python 3. That makes this release very much worth updating to, since Python 2 is no longer receiving security updates and will likely be removed from most distributions in short order.
The release announcement from Cendio can be found on the ThinLinc Community Forum here.
A complete list of changes and enhancements can be found in the release notes here.