DecSync (Decentralized Synchronization) synchronizes RSS, contacts, calendars, tasks and more without requiring a server. It uses a synchronized directory to synchronize the data. This can be done without a server by using for example Syncthing, but any other method like Google Drive or Dropbox also works.
DecSync can also be used to synchronize custom key-value mappings, but currently synchronization of RSS, contacts, calendars, tasks and memos is implemented using the following applications.
To start using DecSync, all you have to do is install some of the applications above and synchronize the DecSync directories.
If you want to use DecSync in your own application, you can use the multiplatform library libdecsync.
Information about the design of DecSync, and how to apply it is given in design.md.
For details about the internal implementation, see spec-general.md.