Syllable Desktop is a discontinued free and open-source lightweight hobbyist operating system for Pentium and compatible processors.

Its purpose was to create an easy-to-use desktop operating system for the home and small office user.

[2] Syllable Desktop is a fork of AtheOS, a free and open source operating system that was discontinued.

[2] Syllable Desktop aimed to be a successor to AtheOS and expand on it, such as adding additional hardware support.

[5] Features according to the official website include: OSNews gave a positive review of Syllable, calling it "astoundingly complete for a hobbyist OS at version 0.5" and praising the speed of the OS, but noting that some features and subsystems were not yet implemented, the limited range of apps, and the occasional stability issues.