Several other tools and frameworks exist that offer some functionality which overlaps with that of NXT. This section describes these other tools and how they relate to NXT.
some of the information here may be out of date
Any errors in the descriptions below are our own. These descriptions are based on published information at March 2004.
The Annotation Graph Toolkit, or AGTK, employs a data model, the annotation graph, which is a directed acyclic graph where edges are labeled with feature-value pairs and nodes can be labeled with time offsets. Structural relationships can be expressed by convention in the edge labelling, but they are not exposed directly in the API as they are in NXT; instead, the focus is on the efficient handling of temporal information. AGTK is written in C++ and comes with a Java port. A query language is planned for AGTK but is not yet available. Although AGTK does not provide direct support for writing graphical user interfaces, it does include wrappers for Tcl/Tk and Python, two scripting languages in which writing such interfaces is easier than in C++ itself. The developers expect interfaces to call upon WaveSurfer, a compatible package, to display waveforms and play audio files.