SplitThreads are enhancements to Split-C by user level non pre-emptive threads. The primary motivation for SplitThreads comes from the fact that the SPMD paradigm of Split-C is a limitation for some important problems. At the same time, Split-C is very efficient and is tunable for good performance. Other related approaches such as Nexus have a large amount of overhead in providing threads capability. This paper presents the addition of a lightweight user-level threads package to Split-C. The performance numbers obtained show significant improvement over existing comparable approaches such as Nexus. The underlying thread library core is QuickThreads. QuickThreads provides minimal support for thread management. Additional functionality is provided by SplitThreads on top of this core. Finally, SplitThreads provides higher level user objects such as I-structures and M-structures