Q: In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Exclusive: Facebook CTO Bret Taylor Departs (For Start-Ups Unknown) 
  
 Facebook’s high-profile CTO Bret Taylor is leaving the Silicon Valley social networking giant later this summer, with future plans to work on an as-yet-to-be-determined start-up. 
  
 The move is likely to be of concern to some over the newly public company’s ability to hold onto entrepreneurial talent, especially in the wake of continued intense media and investor scrutiny over its rocky IPO last month. 
  
 That’s especially true since Taylor has been in charge of both platform and mobile efforts at Facebook, a critical arena for it. 
  
 A pair of Facebook execs under Taylor — Mike Vernal and Cory Ondrejka — will be taking over platform and mobile, respectively. 
  
 Vernal joined Facebook in 2008 from Microsoft, leading the original Facebook Connect project and also working on platform efforts and the development of Open Graph. Ondrejka arrived at the company in 2010 through the acquisition of Walletin; he previously worked at Linden Labs on Second Life virtual worlds. 
  
 While well qualified, they have big shoes to fill. Named to CTO two years ago, Taylor has also been a strong public figure at Facebook events, including its recent developers conference. And he was front and center at Apple’s Worldwide Developers Conference earlier this week at the announcement of Facebook integration into its newest iOS. 
  
 In an interview today, Taylor said he understands that his departure will be perceived as a disruption, although he noted that Facebook had a deep bench of talented technical staff under CEO and co-founder Mark Zuckerberg. 
  
 “I had always been upfront with Mark that I eventually wanted to do another start-up,” he said. “And we felt now is the best time after the IPO and the launch of some recent things for me to do that.” 
  
 That includes the Apple deal, Facebook Camera and also its App Center, which helps users find mobile and desktop apps their friends like. 
  
 Facebook is also reportedly working on a major effort to create its own smartphone, a project known as “Buffy.” 
  
 Taylor, who had previously worked at Google, has a strong start-up background. He left the search giant to found FriendFeed, a once-popular social aggregator. FriendFeed was acquired by Facebook in 2009. 
  
 Noting that his time at Facebook “has been the among the most fulfilling times of my career,” Taylor said that his departure was only part of life as usual in Silicon Valley. 
  
 “Cross-pollination among companies is what drives so much of innovation, so I would not project a lot onto this event,” he said. “I am really confident that the mobile and platform leaders at Facebook can deliver what needs to be done.” 
  
 When asked about the worries he had for the company, Taylor said the challenge of becoming public was top of mind internally. 
  
 “We are dealing with the cultural change of increasing attention, from going from a private company with a lot of scrutiny to a public company with a lot more scrutiny,” he said. 
  
 But he maintained that Facebook’s ability to remain nimble as it grew was strong, noting that the tech side continues to work in small teams. “These details really matter,” he said. 
  
 As for his own future, Taylor said he had not decided the area that he was going to focus on, but that he would be starting something with another former Googler, Kevin Gibbs. 
  
 Taylor said that he would probably focus on an industry he does not understand well as a consumer, as he did when he was working on Google’s mapping efforts. 
  
 “People said we had no sense of direction, so making maps better made sense,” he joked. “That turned out pretty well.” 
  
 Here is Taylor’s post on Facebook about the pending departure: ||||| On its first day of trading, Facebook Inc.'s stock closed barely above its public offering price. It gained 23 cents, or 0.6 percent, to close at $38.23. Since then, the stock price has fallen each week _ until now. 
  
 Here's are the closing prices each week since the first day of trading on May 18: 
  
 _ May 25: Closed at $31.91, down 17 percent for the week. 
  
 _ June 1: Closed at $27.72, down 13 percent for the week. 
  
 _ June 8: Closed at $27.10, down 2 percent for the week. 
  
 _ June 15: Closed at $30.01, up 11 percent for the week. |||||
A:
A top exec is bolting from Facebook so he can work on his own startup. Chief technology officer Bret Taylor, who supervised platform and mobile products, will leave this summer, reports AllThingsD. His leaving could prove worrisome as a reflection of Facebook's inability to retain strong leadership, especially in the wake of the not-so-hot IPO, writes Kara Swisher. Taylor is not saying what his new business will be yet. (He posted a goodbye note on, yes, his Facebook page.) “I had always been upfront with Mark [Zuckerberg] that I eventually wanted to do another startup,” Taylor said. “And we felt now is the best time after the IPO and the launch of some recent things for me to do that.” But it wasn't all bad news for Facebook today: The company's stock closed out its first positive week, notes AP. The stock is now at $30.01, though still well below the $38 IPO price.