Using only one emacs session

[Francis Moreau]

Hello,

After using emacs for a couple of years now, I'm still not satisfied
on the way I'm using it.

I have a couple of emacs processes, each of them dedicated for a
specific task: for example, emacs #1 is used to work on project #1,
emacs #2 for project #2, emacs #3 used for email, irc...

The advantage of this is that each emacs can be customized according
to the project it tracks: for example project #1 has a peculiar
compile command ("make -j4...") whereas project #2 does "gcc -Wall..."
for compiling the project.

Also I like to have some specific buffer layouts to be easily set so I
use the 'window' package: for example I keep in window #2 of emacs #3
some buffers doing irc on a specific irc server.

The drawbacks of that is the multiple instance of emacs: each instance
can't exchange data, emacsclient is more difficult to setup...

So I'm wondering how other people work and if someone found out THE
right answer. I know that some people use only one emacs session for
doing all of their work but for now it doesn't seem very practical but
I'm probably missing something.

Thanks for your feedbacks.