NoMachine is described as 'Access remote computers easily with enterprise-class speed and features supporting any content including audio and video' and is a very popular Remote Desktop tool in the network & admin category. There are more than 100 alternatives to NoMachine for a variety of platforms, including Windows, Mac, Linux, Android and iPhone apps. The best NoMachine alternative is TeamViewer. It's not free, so if you're looking for a free alternative, you could try TeamViewer or RustDesk. Other great apps like NoMachine are Remmina, Parsec, mRemoteNG and TightVNC.
On December 21, 2010, NoMachine announced that NX 4.0 would be closed-source. X2go is free and open source. and offer the same options that nomachine gave and more, most important are: