There are 4 repositories under taskparallelism topic.
oneAPI Threading Building Blocks (oneTBB)
Light-weight header-only library for parallel function calls and continuations in C++ based on Eric Niebler's talk at CppCon 2019.
Tasks In C#
Attempt at recreating https://github.com/cpp-taskflow/cpp-taskflow in Rust
A photo editor built on C# using Task parallelism, TPL library of C# .Net