XBRL - XML Standard for Financial Reporting

XBRL

XBRL stands for Extensible Business Reporting Language. The idea is to create a standard way of communicating business and financial data in a common format that computers can interpret.

Without XBRL, if you want to compare the financials of several companies, you would typically start by collecting the annual or quarterly reports of those companies. After locating the data that you're looking for, which may be in different places in each of the reports, you would probably re-key the data into a spreadsheet where you could run your analysis.

XBRL eliminates the time and effort required to find the data and rekey it. By providing a standard format for the data, XBRL enables you to import the data straight into your spreadsheet and start analyzing it much more quickly.

XBRL has been gaining a lot of momentum over the past few years. It's been in a pilot program for three years and the SEC has recently proposed a rule that would require all US companies to provide financial information using XBRL within the next three years.

Here's a link to the SEC press release.
The AICPA Center for Audit Quality has an XBRL resource page - which is odd, because auditors are not required to sign off on the XBRL data in a financial statement.
The XBRL Consortium has a home page.
An article in the Houston Chronicle about XBRL.