Hi, As SoC officially ended, I wanted to summarize what has been done and not done in the halfedge data structure project ( also the generic geometry library project). - First the concept classes for the different halfedge data structures are implemented. The concepts are hds_concept, forward_hds_concept, backward_hds_concept, bidirectional_hds_concept, facet_hds_concept, vertex_hds_concept, facet_list_hds_concept, vertex_list_hds_concept, halfedge_list_hds_concept, and mutable versions of all these concepts. Each concept class is created in its own file (component), which allowed us to add class level doxygen documentation to all the components and create test files for each component separately. - Archetypes are implemented including the class level documentation and test files for each archetype. - After the concepts and archetypes are implemented and fully tested, we implemented the halfedge data structure itself, which is composed of the following components: -- container_selectors and container_gen: these handle the selection of the containers for different value types, and helper functions for low level manipulation of the STL containers, such as add, delete etc. -- halfedge_selectors and halfedge_functions : the concrete implementation of stored halfedge for various configurations of halfedge data structure, along with various functions to access and manipulate the halfedges. -- facet_selectors and facet_functions : concrete implementation of stored facets along with various functions to access and manipulate facets. -- vertex_selectors and vertex_functions: similar to facets. All the components are again has its own class level documentation, usage example, in code documentation and test files to test all possible selections and manipulations. - Having implemented the main halfedge data structure, along with documentation and full tests, we started adding Euler operators to access and manipulate the halfedge data structure. We first implemented the small functions that are commonly used in Euler operators (stitch functions as its called in code) along with documentation and test cases, later the baseline of the Euler operators are added. The above mentioned implementation took more time than anticipated so although it was in the original proposal, I could not complete the following parts of the project: - Test classes for Euler operators - High level example algorithms such as Delaunay triangulation, and others. - Adapters for existing libraries such as CGAL and LEDA - Full documentation for the project (although currently each component is well documented on its own ) Although the summer of code is officially over, I do plan to work on the project for the next couple of months. I wish to finish the proposed parts and put it in a more complete shape. Finally, I really enjoyed working on the project, learned a lot and gained a lot of experience. I would like to thank the Boost community, and especially my mentor Herve for the opportunity and support. Cheers, huseyin PS: the source code can be accessed from here (from Trac interface): http://svn.boost.org/trac/boost/browser/sandbox/SOC/2007/geometry/libs/hdstl...