A lot of tool support for semantic video annotation is already available, supporting users or even automating tasks on different granularity levels in different metadata formats. In some domains like soccer or medicine, highly specialized solutions are even more advanced and create many new business opportunities. Still, support for mobile Web-enabled and collaborative general semantic video annotation is limited, mostly due to the high costs of developing and running such services. SeViAnno is a long-term development addressing in particular such engineering tasks. The current release is based on RESTful Web services enabling much easier integration of new input and output formats on the metadata management level as well as an easier development process of mobile and Web-based clients. This will be demonstrated by different existing prototypes. Together with a cloud computing-oriented open-source strategy this engineering solution is more sustainable and can be exploited with lower costs.