I'm looking for recommendations for GIS blogs ... specifically GIS *developer* blogs. I'm less interested in the geography than in how apps are put together.

I'd like to keep up with ESRI ArcGIS as well as open source tools.

Which blogs are you fine people reading?
['https://gis.stackexchange.com/questions/32293', 'https://gis.stackexchange.com', 'https://gis.stackexchange.com/users/9795/']
Not always GIS/Map related, but still interesting nonetheless. It's written by a few developers at the New York Times and focuses more on design and prototyping of interactive maps and graphics, and not necessarily GIS applications. Seeing their processes has been really helpful to me. They also use R a lot for spatial stuff, which is cool.

[Chartsnthings](http://chartsnthings.tumblr.com/)
This guy has some great stuff on the ESRI Javascript API. Not sure what kind of development you're doing, but if it's JS, this is a must read!

<http://odoe.net/blog/>