Can webMethods 6.5 developer be opened from its lower versions?
Is your question “Can one use webMethods 6.5 Developer to connect to older versions of Integration Server?” If so, I think the answer is “no”, but its been several years since I have attempted to do so.
Developer 6.5 can connect to IS 6.1. It warns you about constraints upon connection.
you can not use the new functionality of IS 6.5 like service level retry while you are connecting to IS 6.1 using Developer 6.5.
The common functionality of IS 6.1 & 6.5 can be used in this scenario.