Lethe is a wiki implementation with the following main features:
list more features like node import and BibTeX entry export
Using a DVCS provides support for data synchronization between multiple instances, multiuser collaboration and editing history without additional work from the wiki implementation. (History is not exposed yet in higher implementation layers nor user interfaces and concurrent editing is not implemented yet. DVCS tools can be used to access the repository directly and its implementation should prevent data loss when using Lethe for editing.)
It should be easy to deploy on a GNU/Linux system. No dependency on a specific Web or database server is planned (SQLite is used internally). Copying wiki data between multiple machines for editing will be supported: each user can access their own copy of wiki data.
Nodes (less formal and professional than articles or documents) are small and have metadata used for linking and search. They are not identified by titles which are optional and can be easily changed without breaking links. (Nodes have UUIDs which are not directly typed by wiki users.)
Search by titles, tags and title aliases (like redirects in other wiki implementations) is used to find nodes. This supports having smaller nodes with no need to remember exactly how they are named. (Internal links in node text contain UUIDs which can be obtained via search with human-readable terms.)
If you need a more mature wiki implementation or one optimized for multiple users accessing the same instance or working for big wikis like Wikipedia, there are much better implementations to choose than Lethe.
It is also still alpha software and the data format might change, requiring manual migration of existing repositories.