Be sure to consider the terms of open source licensing. Most people believe open source = free software which is not necessarily the case. It is "free" as in free speech, not free beer. Free to view the source code, free to distribute and modify, and sometimes free to license; however, Open source can have two types of licenses, Restrictive (copyleft/reciprocal) and Permissive.
Restrictive licensing requires the licensor makes improvements and enhancements under similar terms (licenses establish a specific trigger for sharing obligations).
Example: GPLv2 - licensee must distribute "work based on the program" and cause such works to be licensed at no charge under terms of GPL
Permissive - modifications/enhancements remain proprietary. Distribution in source code or object code is permitted provided copyright notice and liability disclaimer.
Example: BSD, MIT and Apache.
Furthermore, open source projects typically use other open source which should be carefully used (i.e. perform security scans and compliance) as your End User could be subject to security risks and license liability. According to Black Duck Software, 67% of security audits find open source with vulnerabilities (i.e. Heartbleed - OpenSSL, Shellshock - Bash, Venmon - QEMU, Ghose - GNU C lib).