μ T-License is the license for μ T-Kernel. μ T-Kernel is distributed free of charge from the T-Engine Forum website (http://www.t-engine.org/) and is available to anyone who accepts a μ T-License on-line.
The μ T-Kernel reference code can be freely modified (adapted) to fit the need of devices used. Additionally, products incorporating it can be sold. There is no need to pay a license fee in this case. Furthermore, it is possible to develop software products (development tools such as applications) with the μ T-Kernel reference code and sell (re-distribute) it.
Since μT-Kernel are used in small embedded devices often, it is necessary to optimize not only the hardware-dependant parts but also the shared parts accordingly. Therefore, μ T-License does not strictly prohibit re-distribution as in the T-License. Rather, it actively recommends selling μ T-Kernel as a software product (re-distribution of derivative work).
The differences between T-License and μ T-License are shown in the table.
The big difference is that the distribution conditions of the reference code and derivative works are eased compared to T-Kernel and it can be sold as a software product. However, modified μ T-Kernel source codes need to pass a conformance test to be re-distributed. There is a possibility that an imitation with a different API and behavior may come out because the derivative can be distributed for μ T-Kernel. μ T-License requires passing of a conformance test before re-distribution in order to prevent the distribution of not quite compatible imitation of μ T-Kernel. Other than this, the idea of T-License is inherited and it is a license suitable for development of embedded devices just like T-License.

Table：The differences between T-License and μT-License