Source code is provided, and non-commercial use is free.
You should get latest charm source tree. Here is a table for choosing correct version, for the detailed explanation of the options see the comments following the table. Use this option for networks of workstations, clusters, or single-machine development and testing. This option should be used only after the program has been debugged. The isomalloc-based threads make sure that the thread's stack spans a unique range of virtual addresses across all the processors.