I have launched a personal Wiki platform called MyStacki. The url is : mystacki.com
I have kept the core platform free. Please check it out, sign up for the free account, and let me know what you think.
A quick-start is available at : mystacki.com/#post/18/quickstart.
Screencasts at: mystacki.com/#postsbystack/1/using_mystacki
A brief description of MyStacki.com
“MyStacki is your personal Wiki. You create stacks (topics) of knowledge , which are linked to other people’s stacks, and to Wikipedia. So, say you have a stack for Beatles, under which you have one for John Lennon, another for Yoko; then you would have posts under each of these categories. These stacks will be associated with actual Wikipedia stacks. People with similar interests will find your stacks and ask you to link to their stacks. With each subsequent linking, the total content will organically become richer.”