The rise of Android platform signals the business value and strategic importance of open source software (OSS). While OSS can greatly reduce system development barrier, its license restricts the use of OSS software, and is an important consideration when adopting OSS in system development. Answer the following questions regarding OSS. (1) What is open source software? (5%) (2) About 85% of open source software adopts the General Public License (GPL). What are the key terms of a GPL license? (7%) (3) Apache License is also quite popular in open source community. Explain the reason when the Apache License should be selected over the GPL license for an open source project. (7%) (4) What are the strategic advantages for a business to be involved in open source software development projects? (6%)