The Federal Government should embrace free and open-source software(FOSS) whenever practical. Not only would this result in saving money rather than buying proprietary software licenses, it would also make a statement in support of liberty. The "free" in FOSS refers not to price, but to independence. "Free speech" rather than "free beer".
Also, we- the people- should be able to improve the software our government uses. FOSS provides us that capability. Proprietary software does not. The ability to view source code also means it is much less likely for government software to have malicious code inserted.
Open source means greater security, more citizen involvement in government, and added liberty. Open source is the American way.