Canon XL to EF mount / test and thoughts - YouTube
Metabones Speed Booster XL 0.64x Adapter for Full-Frame Canon EF-Mount Lens to Select Micro Four Thirds-Mount Cameras : Electronics - Amazon.com
Metabones T Speed Booster XL 0.64x for Canon EF-Mount Lens to Select MFT Body (MB_SPEF-M43-BT3) without Support Foot (Check Compatibility!) at KEH Camera
FotodioX Pro Lens Mount Adapter Canon EOS/EFs to Can EOS-XL-PRO