1. Myth: Open source is not ready for the "big time"
This was in the stone age of OSS the most common FUD spread by giants like Oracle and Microsoft. It disappeared many years ago, at least I thought so, http://www.tibco.com/integration/open-source-ESB-alternative, read it and be amazed!
2. Myth: Big companies don't use open source software
They are the ones that historically actually used it first. They had the resources needed to be able to migrate and support them (that is before there was commercial support available).
3. Myth: Open source is not secure enough
Funny enough, this one still lingers.OSS is more secure than closed source. The reson for this is that it is...open...everyone can see it and find out whether it is secure. Ever asked yourself why all the hidden obscure public organisations like NSA are using Open Source?More reading: http://techworld.idg.se/2.2524/1.618946/oppen-kod-motverkar-overvakning
4. Myth: It is difficult to find applications running on open source platforms
Ever used an app?