SquirrelJME is a from-scratch and clean-room built Java Virtual Machine implementation which targets the J2ME/Java ME runtimes which have been historically used for mobile applications such as those running on flip phones. The presentation will go over the unique challenges of implementing a JVM along with differences compared to traditional CPUs. Additionally due to the rapidly changing nature of traditional desktop Java Virtual Machines, backwards compatibility with older byte codes is not a guarantee, therefor there is a specific need for a non-changing run-time environment for these older applications.