CharGer is intended for researchers and practitioners who want to create and edit graphs for CG knowledge bases. CharGer supports most CG features, including actors, contexts, and interchange.

CharGer's current version is primarily an editor to create visual display of graphs.

CharGer is deliberately and explicitly a research tool meant for conceptual graph researchers to explore implementation issues in conceptual graph interfaces.

Using the software will require some familiarity with conceptual graphs, including knowing about concepts and relations, type hierarchies and type/referent pairs. Knowing about actors will also be very helpful.

CharGer is a cross-platform application and it has been tested on Mac OS X, Windows, and LINUX platforms.

NOTE: CharGer is licensed and provided under the terms of the GNU Library or Lesser General Public License (LGPL).

Here are some key features of "CharGer":

General:
· Simple installation procedure
· Requires Java 1.5.0 or later.
· Concepts, relations, actors, contexts, coreferent links are all supported for editing.
· Type and relation hierarchies may be edited and saved.
· Graphs may be exported to: vector graphics formats (EPS, PDF, SVG and EMF), raster (bitmap) graphics formats (GIF and PNG), other applications (OpenCG, Burmeister format, CGIF)
· Graphs may be labeled as to their intent (e.g., query, definition, etc.)
· Contexts are supported, including nesting.
· Negative contexts ("cuts") are supported
· Graph joining on selected concepts
· Graph matching (customizable by modifying matching scheme)
· Make selected concepts generic

Editing:
· Any number of graph windows may be opened for editing.
· Auto-save safeguards to help prevent losing a graph.
· Copy/cut/paste of graphic elements within a graph and between graphs and to other applications
· Undo/redo for most editing changes (limited to previous 10 changes)
· Zoom in and out of a graph
· Shortcut keystrokes to move and explicitly resize graph objects and contexts
· Keystrokes to switch editing tools.
· Ability to set user preferences and save them between sessions.
· Some re-sizing of contexts, concepts, and relation nodes
· Ability to remove referents from a selected set (crude generalization)
· Custom colors for all graph objects, and the ability to set one's own default color scheme.
· Some ability to customize font displays.

Compatibility:
· Portability to all major platforms (i.e., as portable as Java based on JDK 1.5)
· Ability to save and retrieve graphs from files, in an XML format (*.cgx)
· Saving of graphs in CGIF form according to a previous standard (courtesy of Finnegan Southey's Notio) - without layout information
· (DISABLED) Importing of graphs in CGIF form (courtesy of Finnegan Southey's Notio) - without layout information
· View the CGIF form of graphs (courtesy of Finnegan Southey's Notio) - without layout information
· Paraphrase graph into English (other languages in preparation)
· A Wordnet interface is included, where a synset (word-sense) entry can be added to any graph node (requires separate installation of Wordnet 2.0)

Actors/Databases:
· Activation of some built-in actors, including several primitive ones for arithmetic and elementary operations.
· Visual animation facility for monitoring actors as they operate
· Database access through actors, restricted to tab-separated text file "databases" at present.
· Capability to automatically create a skeleton graph from a database suitable for providing database semantics.
· A plugin interface whereby developers can create their own actors and add them to the CharGer.jar file.
· A displaybar actor that will display a referent value in its own graphical display window.

Requirements:

· Java 1.5 or later
· A color monitor, 800 x 600 resolution or higher.