The four remaining defendants in Silicon Valley's closely watched employee hiring case -- Google, Apple, Adobe, and Intel -- have agreed to a settlement, according to a new court filing. The plaintiffs and the companies have reached an agreement to settle all individual and class claims alleged in the class-action suit, according to a letter sent Thursday to Judge Lucy Koh and signed by the attorneys for the plaintiffs and the defendants. The letter was filed in the U.S. District Court for the Northern District of California.