Mapnik is an OpenSource C++/Python toolkit for developing GIS (Geographic Information Systems) applications. At the core is a C++ shared library providing algorithms/patterns for spatial data access and visualization.
Essentially a collection of geographic objects (map, layer, datasource, feature, geometry), the library doesn't rely on "windowing systems" and can be deployed in any server environment. It is intended to play fair in a multi-threaded environment and is aimed primarily, but not exclusively, at web-based development.
High-level Python bindings (boost.python) facilitate rapid application development, targeting zope3, django etc.
Here are some key features of "Mapnik":
· extensible datasource plug-in architecture (ESRI shape files, PostgreSQL/PostGIS)
· anti-aliasing rendering
· expressions based styling
What's New in This Release: [ read full changelog ]
· Rasters: Various fixes and improvements to 8bit png output (#522,#475)
· XML: Save map buffer_size when serializing map.
· SCons: Added new build options 'PRIORITIZE_LINKING' and 'LINK_PRIORITY'. The first is a boolean (default True)of whether to use the new sorting implementation that gives explcit preference to custom or local paths during compile and linking that will affect builds when duplicate libraries and include directories are on the system. LINK_PRIORITY defaults to prioritizing internal sources of the mapnik source folder, then local/user installed libraries over system libraries, but the option can be customized. Sorting not only ensures that compiling and linking will more likely match the desired libraries but also gives more likelyhood to avoid the scenario where libraries are linked that don't match the includes libmapnik compiled against.
· XML: Fixed behavior of PolygonPatternSymbolizer and LinePatternSymbolizer whereby width, height,and type of images is actually allowed to be optionally ommitted (#508). This was added in r1543 but only worked correctly for PointSymbolizer and ShieldSymbolizer.
· Fixed reading of PostGIS data on Big Endian systems (#515)
· PostGIS: Added better support for alterative schemas (#500)
· AGG Renderer Enforced default gamma function on all symbolizers to ensure proper antialiasing even when gamma is modified on the PolygonSymbolizer. (#512)
· PNG: fixed png256 for large images and some improvements to reduce color corruptions (#522)
· PNG: Added new quantization method for indexed png format using hextree with full support for alpha channel. Also new method has some optimizations for color gradients common when using elevation based rasters. By default old method using octree is used. (r1680, r1683, #477)
· PNG: Added initial support for passing options to png writter like number of colors, transparency support, quantization method and possibly other in future using type parameter. For example "png8:c=128:t=1:m=h" limits palette to 128 colors, uses only binary transparency (0 none, 1 binary, 2 full), and new method of quantization using hextree (h hextree, o octree). Existing type "png256" can be also written using "png8:c=256:m=o:t=2" (r1680, r1683, #477)