1) MSN
2) Microsoft Corporation
3) IBM
4) Yahoo!
Explanation:
On June 17, 2019, Microsoft owned GitHub announced that it has acquired US (United States)-based start-up Pull Panda, a firm that creates code review tools for the platform for an undisclosed sum. Pull Panda previously offered its products include Pull Reminders, Pull Analytics, and Pull Assigner as a subscription model. With this acquisition, all these products are now available for free at GitHub Marketplace.Microsoft acquired GitHub in June 2018 for $7.5 billion, one of its largest acquisitions till date.