Almost all software development activities require collaboration and language engineering is no exception. First, there is a need for collaboration among language engineers as it is not realistic to expect one man to master all. Second, there is a natural need for collaboration among language users. Finally, there is a need for collaboration among language engineers and language users: Not only when languages are originally designed but more importantly when they are maintained along with the work already created with them. Unfortunately too often tools ignore collaboration by unnecessarily splitting the work into separate for-mats, tools and roles. We describe and demonstrate collaborative tool capabilities implemented into MetaEdit+ tool and describe experiences on their use in practice.