As far as I know, no older version can open a file created in a newer version, because newer versions add features and the internal structure of the files is therefore different
While a newer program version will often open at least one version back, as soon as you edit and save the file in a newer program the older program will no longer work
You equally share the files, you really need to use the same version
If you don't want a subscription, CS6 may work - Link to buy CS6 via telephone http://www.adobe.com/products/cs6.html
Everyone needs to be on the same version. The CS3 person is completely out of the loop and there’s no way possible to get them a file without CS4.
Best advice is for everyone to move to CC (and no, a CC user does not have CS5.5. The subscription includes CS6). Otherwise you have a disaster in the making.
Hmmm. I've had both freelancers tell me that cc provides access to all the old cs versions. Too good to be true I guess.
Sent from my Verizon Wireless Smartphone
Just CS6. If this is a short term project you can go with a month to month subscription but be aware that system requirements and supported systems vary by version.
Best thing to do is download the 30 day trial that way you get a free month anyway. Then go month to month if you have to.
As Bob says, only CS6 is include. But it is NEVER a good idea to work in a collaboration with different versions as any conversion makes changes and backward compatibility is only limited. If these coworkers are making their money with using software, they should invest it in the CC subscription.