We are have a WHMCS Opennebula Module developed and need the correct PHP API documentation to provide the the developer. We can only find ruby and java docs and we did send these to the developer however he stated that WHMCS requires PHP.
Once complete we will be offering this module commercially to further improve the uptake of Opennebula. Eventually we will invest to have the module compatible with other popular billing systems. Having a professional module with a professional company providing support for the module can only benefit Opennebula as the majority of commercial users will want a provisioning module that can be integrated with their existing billing systems. There is one WHMCS module already out there however based on other users there is no support and the module itself is not ideal and with many issues. We hope to overcome that.