The document summarizes the evolving test used by the Federal Circuit Court to determine personal jurisdiction in declaratory judgment patent cases. The Federal Circuit applies a three-part test: 1) whether the patentee purposefully directed activities at forum residents, 2) whether the claim arises from or relates to those activities, and 3) whether exercising jurisdiction would be constitutionally unreasonable. Sending a cease-and-desist letter alone is insufficient contact, but adding an exclusive license with a forum resident satisfies the test. The test balances a patentee's ability to enforce patents against subjecting them to distant forums.