NX 3.5.0 is made up of many different pieces, some of them being new programs and libraries created by NoMachine with the purpose of implementing the NX system, others being modifications to existing OSS software, intended to provide additional NX functionalities or improved interoperability with the NX environment.

Most of the software developed by NoMachine is released under the GPL license. This includes the NX X Protocol Compression libraries and all the modifications to existing OSS software created by NoMachine, as for example, the modifications to the X-Window System's components.

Some NX components, such as the nxserver and the nxclient executables and underlying libraries, are commercial software, developed by NoMachine under a closed source license. These components are designed in a way that they allow interoperability with the GPL'd components without requiring the source code of nxclient and nxserver be released under an open source license. This allows for either proprietary versions and open source versions of the NX system, both sharing the same core components developed by NoMachine under an OSS license.

NoMachine owns the copyright on the NX source code, including the parts that represent modifications to existing software. NoMachine requires that copyright be assigned to NoMachine for changes to the NX code-base. In order to avoid patent disputes and other legal controversies, contributors will have to sign a copyright transfer form, if they want to contribute non-trivial modifications to the NoMachine NX software.