Salesforce.com’s Dreamforce event, the annual week-long software conference in San Francisco, starts today, after a full weekend “Hackathon” where developers competed for $1 million in prizes.

The “Hackathon” began at 6:00 p.m. Pacific time on Friday, and pitted thousands of developers against each other to build the best mobile apps in three categories: Force.com mobile apps, Heroku mobile apps, and Force.com with Heroku mobile apps. The first-place individual or team in each category wins $100,000, and the three category winners will then compete for an additional grand prize of $150,000, which will be awarded by Salesforce CEO Marc Benioff on October 16.

According to BetaWired, out of the 135,000 expected Dreamforce attendees, nearly 25,000 are likely to be developers competing in the Hackathon. Now in its twelfth-year the conference is being promoted as the “world’s largest software event ever.”

“At Dreamforce this year, attendees will see the future of cloud, social, mobile and connected technologies and how companies are connecting with customers in a whole new way,”said Benioff in a statement, according to PC Mag.

The Hackathon is only the beginning. This year, Dreamforce offers more than 1,450 breakout sessions, and a number of big-name guests. Former U.S. Secretary of State Hillary Rodham Clinton and former Vice President Al Gore, as well as musicians Will.I.Am and Neil Young will speak at the event. The entertainment lineup features Bruno Mars and Cake.

Dreamforce 2014 will also highlight a renewed focus on charitable activities, including a food drive to collect one million meals.

“We are not only creating the future of our industry, we’re working to create a better future for everyone,” said Benioff.