I am a developer, and I'm responsible to maintain 3 different systems, one is programmed with jdev 11g and ADF, another with forms 6i and another with forms 10g .
The problem is that when I barely make the windows 10 64-bit machine work the 6i with the 10g the Jdev stops walking, or its weblogic goes crazy, when I correct the errors in jdev one of the two forms or both stop working. I have reinstalled and reinstalled everything several times, I have been doing this for a week and a half and I do not get the formula, Has anyone had a similar experience? Is there hope that these tools coexist or is it better I use separate virtual machines?
I have an XP SP3 virtual machine with 4GB of RAM in a server, where I have both forms but it is very slow.
What do you advise me to do?
From my point of view, I'd suggest having 3 separate virtual machines, one for each development tool. Operating system version and Oracle software version should match (i.e. Oracle tool should have been certified on Windows version you put onto the virtual machine). Forms 6i is really ancient, but many people still use it (we have it too), so you can't really expect to make it work properly on a brand new Windows 10. I've read that there are "hacks" that make it possible - I prefer porting my virtual machine to a new computer when necessary, without having to install and configure everything from scratch.
As you wouldn't be running all 3 virtual machines at the same time (would you?), it doesn't matter whether computer you install them on is very powerful or not. For example, my PC has 8GB RAM. I designated 1GB to my Developer 10g virtual machine (along with 10GB disk size), put Windows XP SP3 onto it and everything works just fine. When I had PC with 4GB RAM, I used 512MB RAM on virtual machine - no problem either.
There's no need to run virtual machines on the server (if it is slow), if your own PC is a better choice.
Although it is possible to run multiple Oracle software products on the same computer (you'd install each of them into its own Oracle Home (i.e. directory)), problem arises when they seem to collide (as you described it - you make one of them work, which causes another two to fail).
Therefore, yes - it is an opinion-based answer, but I'd suggest 3 virtual machines.