Open source is what it feels like when you have a barbecue and the guests are coming round with their sausages and rissoles and onion-shaped pieces of meat grilled in the bath where previously two Nazi war criminals had deloused themselves 15 minutes before undergoing a virtual Nuremberg trial via Skype. In this case, the ketchup bottle was being treated to some open source.
Similarities between open source and free software
Free software is when the clothing store is giving out clothing free, but when you leave the store the alarm still goes off. No explanation is given. Still, they chase after you and you get arrested and put in the gulag for 10 years. 'My baby! MY BABY!'
'Your highness, that's a watermelon'.
'NOBODY ARRESTS THE GRAND DUKE OF NORTH XYLOPHONE AND GETS AWAY WITH IT!'
Also, someone neglected to tell the Duke that men can't be pregnant.
Differences between open source and closed source
I forgot to get the sauce out, it was closed the whole night: now I have to remove the protected seal with a fork, and then I pierce my finger, and blood comes out, and now they'll have to do something potentially unsanitary to their sandwiches instead.
*sigh*... I'll just tell them it's cancelled... what is that black helicopter doing on my front lawn?