in short
Microsoft and Facebook today jointly launched a new initiative called the Internet Bug Bounty program. In short, the two companies are looking to secure the Internet stack by rewarding anyone and everyone who hacks it, and responsibly discloses vulnerabilities they find.
"in short" means "to sum up." I often use this phrase in Japanese to connect sentences. There are also similar expressions like "in brief", "in a word" and "in fact". Although it is superfluous to say so, I know the sentence after them is not "short" neither "a word" sometimes.
Refs
words, 13-11-07 22:23, 14-02-25 17:51, Yosei