The tool we'll be mainly looking at today, and a really great foundational open source library for rendering slippy maps.
Originally created by Mike Bostock at and for the New York Times, D3 (data-driven documents) is a javascript library for rendering data visualizations as SVGs. It's pretty vast and covers a lot of use cases, including maps. Here is one intro to mapping with D3.
ESRI basically dominates the market for GIS software. They kind of are GIS software. You will run into their proprietary data format, the shapefile, pretty much all over the place. It's really expensive software, but universities often have licenses if you're a student and want to try or learn it.
Pretty much the only open source desktop GIS software out there. It's clunky as hell sometimes but gets the job done. Created originally by Boundless, a company described in more detail further below.
A lot of the platforms and open source tools currently available for web mapping are products supported by companies. We're not going deep into the specifics of these platforms and tools mainly because (1) I didn't really want to waste time on people registering for accounts and API keys and (2) these companies are all really, really good at documentation of their products and I am pretty sure you're all perfectly competent people.
In addition to information about their specific tools, I've included some background on the companies--software doesn't emerge from a vacuum.
TLDR
Basically, if you are working with anything OpenStreetMap related, you're going to run into tools built by Mapbox. And the tools they build are actually pretty great.
Who They Are
Mapbox is about 6 years old, and began as a project from Development Seed, a boutique data visualization studio working with NGOs in Washington, DC. Mapbox's tools were, essentially, tools Development Seed needed to do their work, and they realized there was a solid business opportunity in making those tools available to others. They also offer one of the few alternatives to Google or Bing satellite imagery, in partnership with Digital Globe.
Mapbox currently has offices in San Francisco, Washington, DC; Bangalore, and Peru. Their funders include The Foundry Group, DFG, DBI Investors, Thrive Capital, Pritzker Group, and Promus Ventures.
What They Offer:
cartodb.com
TLDR
If you want to work with really large datasets and prefer styling in a GUI, this is a super useful service.
Who They Are
CartoDB was founded in 2012 and has offices in Madrid and New York City. Their funders include Accel Partners and Salesforce Ventures.
What They Offer
CartoDB is basically a platform-as-service model company that provides users with a nice interface for working with hosted geodata. It's basically a dashbaord for PostGIS with a styling wizard tool, and some helpful APIs for integrating and pulling CartoDB-hosted data onto a map.
mapzen.com
TLDR
Super-cool products, which are finally starting to kind of stabilize, but not necessarily production-ready tools.
Who They Are
Mapzen started in 2013. It's an R&D lab disguised as a startup, currently being funded entirely by Samsung. As far as anyone can tell it's a gamble within Samsung to see whether building out better open source mapping tools will offer better alternatives to Google Maps, so that Samsung can eventually fork Android and build their own OS without needing Google tools, like Maps. Whether that will work is totally anyone's guess.
What They Offer
(Fact: all of Mapzen's libraries have way, way better names than the API services)
TLDR
Built many of the open source tools that are the foundation of working with spatial data online. You will probably never actually have to give them money.
Who They Are
Originally called OpenGeo, Boundless was an open source lab working on really awesome mapping tools. They got a rebranding and new business focus when they got a huge round of funding from In-Q-Tel, the CIA's venture capital firm. Have subsequently been spooky and unsettling AF, but their open source tools remain open.
What They Offer/Built