We've just launched a new REST API which supports Conversion of the full range of Office and Image formats as well as creating from scratch using Templates and a lot more like barcode recognition and (soon) OCR. We're just getting ready to complete our BETA stage and looking to get more people to try it out.

We have some Ruby sample code and a Heroku add-ons is in the works.

Please check it out - I'm looking for as much feedback as possible at this stage: http://saaspose.com