µC/OS-III is a completely new real-time kernel with roots in µC/OS-II. Portions of the µC/OS-II Application Programming Interface (API) function names are the same, but the arguments passed to the functions have, in some places, drastically changed.
This section explains several differences between the two real-time kernels. However, access to µC/OS-II and µC/OS-III source files best highlights the differences.
The table below is a feature-comparison chart for µC/OS-II and µC/OS-III.