A year ago, we struggled to get rudimentary data out of government. Today we're seeing the biggest and most comprehensive release of spending data in British history.

The Government has released an enormous amount of data - some 157 spreadsheets containing every transaction by each one of 24 core departments detailing every item of spending over £25,000. Independent developers, graphic artists and even us here at the datablog journalism team at the Guardian have had embargoed access to it for over a week. So, what is it?

It's the latest in a series of major data publications by the government, which came into power determined to unleash a "tsunami of data". So far, publications have included the enormous Treasury database, COINS; salaries of senior civil servants; staff numbers and the detailed organisational structure of each department.

The data itself covers over 194,000 individual transactions, payments to suppliers and bills covered by government departments in the first five months of the life of the Coalition. There's lots excluded, though: the NHS, benefit payments, spending by quangos, information removed for "national security" and personally confidential reports. It's about £80bn of an annual spend of £670bn.

We figured 170 spreadsheets is too much for most people to browse, so Guardian lead software architect Matthew Wall has built this useful spending data explorer app. It's designed to make it easier for you to search and download the key data you're interested in.

We may even have done some of the analysis you're looking for already. We've combined spending for each department into single spreadsheets. Here's what you can find:



• Sheet 1: Every item for the department

• Sheet 2: Detailed breakdown of type of spending

• Sheet 3: Broader breakdown into fewer areas

• Sheet 4: Every supplier listed in alphabetical order and by size (watch out on this one for different spellings of the same supplier)

What can you do with the data?

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