Azavea Labs

Where software engineering meets GIS.

Putting the Fun in FOSS

I went to the State of the Map (SotM) and Free and Open Source Software for Geospatial (FOSS4G) Conference in Denver, CO last week, where I was surrounded by geospatial users, developers, and architects. I had the opportunity to attend some workshops and learn about a slew of awesome projects — I’m itching to start incorporating many of these new tools and techniques into our solutions.


I was able to attend some of the workshops — “You’ve got Javascript in your backend” with Node.js and Polymaps was a great beginner workshop, introducing lightweight servers and client mapping libraries. I was amazed that a basic web server in node.js is only 5 lines of code. Equally amazing was seeing what capabilities Polymaps had when it weighted in at only 32K (minified) vs. OpenLayers at 1.2M (minified default build).

i2maps + pico

Some exciting visualization tools are coming out of the National Center for Geocomputation at the National University of Ireland, in the form of i2maps. While it’s relatively immature (not much in the form of documentation), most the basic functionality builds off of OpenLayers.  Since I’ve already learned the OpenLayers library, I has a short learning curve, and was able to get up to speed pretty quickly.  Their library incorporates some awesome features like dynamically loading and evaluating rasters via canvas (this only works on modern browsers), and even agent-based modeling. I could have stayed in that workshop for a week.

A byproduct of the i2maps project is pico. Pico is a bridge between Python and Javascript, enabling you to call native Python methods directly from Javascript. It performs all the plumbing for you, allowing you to write a simple callback to handle your method’s return value. It also takes care of converting Python objects into Javascript objects, allowing you to pass all sort of data back and forth (including rasters!).


Another new project from a contributor to the MapServer project is mod-geocache, a tile caching service as an Apache module. This skips a lot of overhead (no proxying, no interpreters, no CGI), and is very fast. In addition, the C implementation has excellent speed and performance. You can perform on the fly tile merging, quantization, and recompression. I’m excited about this module, and the promise of caching with an Apache server (looks like it has more features than mod_tile).


Geoserver‘s next release is also going to include some great features. The ones that really jumped out at me:

  • Time and elevation filters — e.g. storm tracking, where you can limit the features by a time field.
  • Styling SLDs in data units — e.g. “road is 5m wide”, and changes dynamically with scale. This greatly simplifies scale-dependent renderers.
  • Georeferencing of layers can be done in the admin interface.
  • Layers can be view definitions — you don’t have to roll your own views prior to creating the layer.
  • Virtual Services — partition the data layers by workspace.

These aren’t all the new features; take a look at the laundry list yourself, and prepare to be impressed.

Mapnik 2

I think the reason for calling it Mapnik2 is that it is literally twice as awesome as it was before. I learned about the new features in Mapnik2 in the lightning talks at SotM, and I think this was one of the few talks that made you feel like you were actually struck by lightning. I can’t remember half the slides in the talk, but the supported formats, reprojection, styling, and speed improvements left me with my head spinning.