If you are looking for a stable platform for creating and using wikis, this is the one that I recommend. I have used it for several years with students and K-12 teachers. Wikispaces is supportive of K-12 teachers. Free monthly webinars are offered to keep folks informed of current uses and possibilities. Our campus has a learning management system that has a wiki tool built-in, but it is very unstable and limited compared to what wikispaces offers. I am well-pleased with Wikispaces and how it stays current with the ongoing changes in digital technology.