It's not just about who has the bigger tree and the better eggnog. Tech companies in SF are, once again, competing to delight their workers in a holiday party proxy war.

Yahoo recently held a Wizard of Oz-themed event at Pier 48 with an appearance from Janelle Monae, while Chromeo put on a show over at a Dropbox shindig. Last year it was a blue-lit City Hall for Twitter, but for this year's iteration the company rented out the Exploratorium. Not to be outdone, Facebook booked AT&T Park, posing with the Giant's World Series trophy and donning custom jerseys. Google threw bashes at the Academy of Sciences, City Hall, and aboard the USS Hornet in Alameda for its various departments. And maybe overdoing it according to some partygoers, LinkedIn threw down at Levi’s Stadium, bussing thousands of revelers to and fro.

As the Chron reports, analysts say companies deem holiday parties a key to pleasing and impressing their employees. It's just one part of an escalating perks arms race, and it stands out all the more starkly as Wall Street cuts back on its lavish image and culture.

Here's a basic party-cost estimate, by way of example: Last year, Twitter paid the city $73,100 to rent City Hall for their party, and if food and drink cost $100 per person, the bill for the food and drink alone would have added up to $290,000.

Critics might say that these events symbolize tech's "lease" on San Francisco, but anyway, check out some of the pictures below, and "God bless us, everyone!"

These are pictures from Google's cloud and search joint party at the Academy of Sciences, which was Sherlock Holmes themed, had a high-end whisky bar, and had a lavish spread of English pub food, charcuterie, and sushi. Also: actors on stilts dressed as London policeman.




Here's Facebook's big, 17,000-person fete at AT&T Park:

SF Giants. #FBholidayparty #FBparty #fbpartyinthepark

A photo posted by Chloe Park (@chloepark) on

Got to see a whole bunch of friends and coworkers and take in gorge views around AT&T park. #fbpartyatthepark

A photo posted by Zainab Ghadiyali (@zainabghadiyali) on

This would be Twitter's buyout of The Exploratorium:

Think this topped last year! #twitter #exploratorium #celebrate #cheers #taintedlove

A photo posted by Chris (@tophe_gear) on

And, finally, Twitter apparently had a cocktail-making robot at their shindig.

A bartending robot! #twitter #holidayparty

A video posted by @sinleeloh on