duncan bayne writes "My company is developing some software using Ruby. It's proprietary software — decidedly not free-as-in-beer — but I don't want to tie my customers down with the usual prohibitions on reverse engineering, modification, etc. After all, they're licensing the product from us, so I think they should be able to use it as they see fit. Does anyone know of an existing license that could be used in this case? Something that gives the customer the freedom to modify the product as they want, but prohibits them from creating derivative works, or redistributing it in any fashion?"