If I use EPL licensed software ( namely Eclipse jars ) in an application, do I have to give the users the source code and the right to redistribute? If that is not the case, what rules should I follow if I use EPL licensed software libraries in an application that I wish to distribute?
IANAL, but the Eclipse Public License (EPL) does not require distribution of require access to the source code.
On the characters of the EPL let me quote the GNU people:
The Eclipse Public License is similar to the Common Public License, and our comments on the CPL apply equally to the EPL. The only change is that the EPL removes the broader patent retaliation language regarding patent infringement suits specifically against Contributors to the EPL’d program.
And another quote on the Common Public License Version 1.0
This is a free software license. Unfortunately, its weak copyleft and choice of law clause make it incompatible with the GNU GPL.
‘Weak copyleft’ in this quote means that you are not required to use the same license for a derived work. So you can take EPL licensed code, include it in you own work, and distribute the result under a non-free, proprietary license.
Edit:
For details on what you are required to do as a user of EPL licensed software, see ‘3. REQUIREMENTS’ of the EPL:
iv) states that source code for the Program is available from such Contributor, and informs licensees how to obtain it in a reasonable manner on or through a medium customarily used for software exchange.
See also this answer: https://softwareengineering.stackexchange.com/a/138656/34768
4