I am at a new company and one of our goals is to implement a document search portal for our team and our clients. I am a bit worried that if we use an external service provider like Salesforce or some other ECM in the cloud there will be a lot of integration work in the future. From a client perspective, these documents will also exist in the same bucket as our structured content (stored in the DB, not a MS Word doc).

If you have implemented document searching, what languages, frameworks, and technologies have you used? Do you have any failure stories? I don't have a problem using something out of the box, but I think it is important that we have control over the documents and the API to access them. I would like to use Rails if we go fully custom.