Mapnik

Mapnik powers most of the web maps you encounter day to day. Mapnik is a Free Toolkit for developing mapping applications. Above all Mapnik is about making beautiful maps. It is easily extensible and suitable for both desktop and web development.

##Why upgrade to version 2.0 (over 0.7.x):

• TileMill/Carto produce (can export) Mapnik XML compatibile with only Mapnik 2.0.0 and above.
• Use per-feature attributes from table for CSS values instead of absolute values.
• Resolution independent rendering (Retina) - For 144 dpi etc images using the line weights in the CSS instead of needing to change them.
• Postgis 2.0 support
• New MarkersSymbolizer - allowing you to draw circles of arbitrary size
• [On-the-fly Raster reprojection] (http://mapnik.org/news/2011/09/16/new_raster_reprojection)
• Massively faster rendering during reprojection (e.g. from wgs84 to spherical mercator) under high load/threaded server
• XInclude support in Stylesheets
• More robust clipping of map extents to support more fancy projections
• Global alignment option for polygon pattern fills
• Added support for drawing only first matching rule using filter-mode="first" in Styles Support tix - This should likely be leveraged by Cascadenik to reducing the amount of filter combinations needed.
• Codebase is optimized
• Made styling syntax more consistent
• Looks like there is a branch of Cascadenik that works with Mapnik2?

Version 2.1 (coming soon):

• [Advanced, nested text styles for fallback placements] (http://mapnik.org/news/2011/09/02/text_formating/)
• Much better support for labeling multigeometries Examples
• Massively faster rendering at high zooms using better geometry clipping
• Polygon and line bezier smoothing
• New CSV plugin to render directly from tabular data (that includes WKT column or lon/lat columns)
• Less memory usage with heavy data like OSM
• Infinite zooming support (you previously could not zoom past z18-19 without problems if your data had polygons)