The fight over the advantages of commercial versus open source software are at least as old as the creation of the GNU operating system (1983).

Now in the face of revelations by former NSA contract worker Edward Snowden that the agency can seemingly break into almost anything comes an argument that the open source Mozilla Firefox browser is the safest there is.

It’s made by someone who is admittedly a bit prejudiced about the matter: Brendan Eich, CTO of Mozilla. In this blog  he uses the old saw of ‘trust but verify’ to advise IT professionals to take a close look at the tools they use.

“Mozilla has one critical advantage over all other browser vendors,” writes. “Our products are truly open source. [Microsoft’s]  Internet Explorer is fully closed-source, and while the rendering engines WebKit and Blink (chromium) are open-source, the [Apple] Safari and [Google] Chrome browsers that use them are not fully open-source. Both contain significant fractions of closed-source code.”

By contrast Firefox is completely open source, he says, so everyone can see the source code and developers around the world can detect any flaws. In fact, he argues, organizations can verify the executable parts of Mozilla browsers by building Firefox from source code and comparing the cod with the official distribution.

Admittedly, that will take some time and resources, which some organizations may not have. But Eich maintains that through international collaboration with developers users can have confidence Firefox can’t be subverted without notice.

Worthy advice, or jumping on the Snowden fear bandwagon?