The xtb program (Linux version only) can be obtained freely for academic use upon request. Please contact xtb@thch.uni-bonn.de for details.
 

• A GitHub repository is available here.
• Link to the binaries
• Online User Guide
• The crest binary (Linux systems only) can be downloaded from its GitHub repository (https://github.com/crest-lab/crest).
• subscribe to the xtb-user list