The information in this wiki hasn't been maintained for a good while. Some of the projects described have since been deprecated.
In particular, the "Ushahidi Platform v3.x" section contains information that is often misleading. Many details about this version of Platform have changed since.
This website is an extraction of the original Ushahidi wiki into a static form. Because of that, functions like logging in, commenting or searching will not work.
For more documentation, please refer to https://docs.ushahidi.com
You can search by keyword and even #hashtags (if the #hashtag is used in Crowdmap.
Anyone can create a map. Search for all the "public" maps. Then, you can "follow", "comment" or even join in the map project.
(future feature)