He said he knew people were sceptical about politicians' pledges but said these were "not general pledges without details, without tests, without scrutiny".
He promised new ways of measuring progress against the pledges online, and said cabinet ministers would have to sign up to public, annual contracts outlining what they were expected to deliver.
Their positions would be subject to delivery - "just as it would be in a business or any other organisation", he said.
He also said the head of the civil service, Cabinet Secretary Sir Gus O'Donnell, would be asked to "performance manage" departments' top civil servants against their delivery of the pledges.
Web founder Sir Tim Berners-Lee was working on creating "maximum possible information available to the public at all times", he said.
'British people first'
"This rapid extension of transparency will show in real time how government are delivering against our pledges."
Mr Brown added: "We will put the British people first, before personal interests, before our party interests, before any vested interests.
"We are the people's party and we are pledged to serve the people."
But in his own speech to activists, Mr Cameron said he had thought Mr Brown might have "finally summoned up the courage" to call the election but said instead he was taking people for "fools".
"He says in future he's going to have a contract for each cabinet minister, detailing what you expect them to do. What a great idea.
Labour has defended the pledges against criticisms of "vagueness"
"Just imagine if this contract had been written for the Parliament we have just had - that the contract with Alistair Darling was to double the national debt and give us record youth unemployment... What a complete nonsense.
"Once again the prime minister taking people for fools, not deserving re-election, and that is what we are going to stop."
He said there was a "big choice" at the general election: "This election is going to take place, we have at most before May 6, 40 days and 40 nights to make our case and to bring change to this country.
"That is the time that we've got left to win this great argument - do you want to stick with what you know or do you want change with the Conservatives?"
He added: "We are ready to fight it whenever he is ready to call it."
Mr Clegg said: "It is astonishing that after 13 years in charge, the best Labour can come up with is a list of vacuous pledges wrapped up in management speak.
"Between them Labour and the Conservatives have failed to come up with a single specific positive reason to vote for them.
David Cameron: "It's the biggest display of brass neck in British history"
"This is the old politics and the old politics is simply not good enough anymore."
Plaid Cymru's leader at Westminster, Elfyn Llwyd, called the pledges "vague and meaningless," adding it was "quite simply an insult to the intelligence of voters that they now expect people to believe they'll actually do all this".
Mr Brown later addressed Scottish Labour's spring conference in Glasgow, where he reiterated the party's election pledges.
But the Scottish National Party's leader at Westminster, Angus Robertson, said no-one believed Labour's "empty promises".
"Labour remain in denial over their disastrous economic mismanagement which has taken the UK to the brink of bankruptcy and led to the highest level of UK debt ever," Mr Robertson said.
Earlier Mr Brown told the Guardian he would keep Alistair Darling as Chancellor if Labour wins - there has been much speculation he would be replaced by Ed Balls.
The PM also said victims of anti-social behaviour would be allowed to use public funds from their local authority to take out civil injunctions, if police were too slow to act.
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