Starting in 2013, with the release of version 4.0, NX became closed-source. In 2010, the company announced they would be releasing the technology under a proprietary license. The last update to this open-source version was released in 2012. The core compression technology was released under the GNU GPL2 license (NX 1) for Linux servers, whilst other components such as the NX Server and NX Client programs remained proprietary, on February 14, 2003. It wrapped remote connections in SSH sessions for encryption. In 2003, the compression and transport protocol NX was created to improve the performance of the native X display protocol so it could be used over slow connections such as dial-up modems. NX's design was derived from the Differential X Protocol Compressor project (DXPC). It is developed by the Luxembourg-based company NoMachine. NX technology, commonly known as NX or NoMachine, is a proprietary cross-platform software application for remote access, desktop sharing, virtual desktop (on Linux only) and file transfer between computers.

Ubuntu nomachine authentication failed