IBM introduced the first product WebSphere Performance Pack, in June 1998. and As of 2010 it forms a part of IBM WebSphere Application Server Network Deployment. IBM offers a free WebSphere Application Server Community Edition along with an paid license Enterprise Edition. In many ways Websphere is a family of products ranging from SOA embedded server appliances to E-Commerce editions. For certs etc, please look here.
And WebLogic now owned by Oracle Corporation, and it consists of a Java EE platform!
it includes : Java EE application server, WebLogic Application Server; WebLogic Portal; Enterprise Application Integration platform; Transaction server and infrastructure; WebLogic Tuxedo and Telecommunication platform, WebLogic Communication Platform…. It has very strong support for high end architecture features such as clustering and scalability. It has formed the delivered underlying application server architecture to many Oracle applications such as PeopleSoft although this is now changing with Oracle Fusion Middleware. For Certs etc, please visit here.
It is not possible to measure which certifications are better than which ones…. In general, IBM and BEA (Oracle Corp) provide vendor-specific certifications, while Sun provides vendor-independent certifications, i.e. JBoss. It also depends on you as well that how are you enjoying, when you are working, because job satisfaction is also a matter!