Editing and design of biological structures

Bioclipse
Free Software
Free
Offline
http://www.bioclipse.net/

Bioclipse is a free and open source workbench for the life sciences. 

Bioclipse is a rich client, which means it is a downloadable application that run on your local computer but also gives the possibility to communicate with servers for data retrieval and computational services. The powerful plugin architecture is based on Eclipse, and results in a responsive, integrated user interface designed for simple and intuitive operations that at the same time is easy to extend with custom functionality. 

Bioclipse is based on the Eclipse Rich Client Platform (RCP) which means that Bioclipse inherits a state-of-the-art plugin architecture, functionality, and visual interfaces from Eclipse, such as help system, software updates, preferences, cross-platform deployment etc.

Bioclipse provides advanced functionality in fields such as cheminformatics, bioinformatics, semantic web, spectrum analysis, drug discovery, safety assessment, and general chemistry education.

Bioclipse is developed as a collaboration between the Proteochemometric Group , Dept. of Pharmaceutical Biosciences, Uppsala University, Sweden, and the Cheminformatics and Metabolism Team at the European Bioinformatics Institute (EBI).

Bioclipse is released under Eclipse Public License (EPL) + exception, see the License Statement, putting no constraints on choice of backend and/or license for creating plugins for Bioclipse; it is totally open for both open source plugins as well as commercial.