Awesome

Salt

language-independent Salt supports a huge set of languages and typesets. Each language which can be expressed in UTF-8 is supported by Salt.
theory-neutral Salt is open to any linguistic school or theory, not limited to a specific one.
tagset independent Salt is not bound to a tagset. Annotations are represented as attribute-value pairs and can be chosen freely.
open source Salt is licensed under the Apache License, Version 2.0 and published on Github.
multimedia support Salt is a text-based model, but also supports the modeling of audio and video corpora.
annotation layer independent Salt is not limited to a specific set of annotation layers. Since Salt is a graph-based model, you can model many different structures, such as tree structures, span annotations, coreference chains and so on.