New API version now released: corporate networks, custom filtering, financial accounts, etc

What is OpenCorporates?

OpenCorporates aims to do a straightforward (though big) thing: have a URL for every company in the world.
Is that all?
Well, no useful though that would be, we're also gradually importing government data relating to companies, and trying to match it to specific companies
Why do this?
Few parts of the corporate world are limited to a single country, and so the world needs a way of bringing the information together in a single place, and more than that, a place that's accessible to anyone, not just those who subscribe to proprietary datasets. See also the OpenCorporates Principles
There are quite a few countries you're missing
We've grown from 3 territories and a few million companies to over 75 jurisdictions and 55 million companies, and are working with the open data community to add more each week.
How can we get hold of the data?
We have a new API service, as well as our highly popular Google Refine reconciliation service (see documentation), and this allows access to the information as JSON or XML. If you need data in bulk, either for academic research work, for another cool open data project, or commercially, drop us an email at info@opencorporates.com.
Under what licence is the data published?
In collecting this information, and matching up to other data, OpenCorporates has acquired database rights, but we strongly believe this information should be freely reusable, and so make it available (to the extent that we have the rights) under the share-alike attribution Open Database Licence. For details, please see our licence page.
Who's behind OpenCorporates?
The company behind OpenCorporates is Chrinon Ltd (Registered in England, number 07444723), and the people who founded it are Chris Taggart and Rob McKinnon. Rob built TheyWorkForYou.nz and WhosLobbying.com; Chris built OpenlyLocal.com and OpenCharities, and sits on the UK Government's Local Public Data Panel, the UK's Tax Transparency Board, and Open Knowledge Foundation's open government working group.
What sort of governance is there?
We have an Advisory Board made up of highly respected and independent experts in the field of transparency and open data to advise us, and to ensure that we never deviate from our core principles
How can we help?
If you're in countries we're not yet covering, you can help us by finding out where and how the basic information is available (e.g. official company registry website), and whether there's a single or multiple jurisdiction (some countries allow regions or states to register companies). We're collaborating with ScraperWiki to help get the basic company data (specifically the company name and number). See the OpenCorporates blog for more details or email us at info@opencorporates.com
I think there are errors in matching the companies
It's possible. We use a number of algorithms to match companies. If governments made more data openly available, or kept a record of the company numbers of the companies they do business with, it would be a lot easier. It would help too if companies were forced to put the company number on their website (in the UK they're supposed to but as often as not they don't). Email us and we'll fix it.