Portable CLU is a CLU compiler intended to be easily portable. It uses C as a back-end, and then uses the local C compiler to create a binary. Portable CLU is no longer under active development, however it is by far the most recently maintained CLU compiler, and it is possible to get it to run on a reasonably modern system.
An unofficial "updated PCLU", which has been fixed to work with the latest version of GCC, can be found on GitHub. The updated PCLU will run on a modern 64-bit Linux system.