I don't know why people advise others to splat their compiled 3rd party software all over /usr/local when /opt is there specifically for that purpose.

Also, enabling pthread on 1.8 has some significant performance problems unless you're using REE. For more reading on that:

http://timetobleed.com/fix-a-bug-in-rubys-configurein-and-ge...

i don't see a difference between /opt and /usr/local , I just think it's a matter of preference

The difference is stuff installed in /opt is encapsulated inside its own folder, whereas everything in /usr/local is shared (one bin dir, one lib dir, etc).

So if I want to uninstall Ruby from /opt I do something like this:

    rm -rf /opt/ruby-1.8.7

To uninstall Ruby from /usr/local is a lot more work.

you could actually do the same in /usr/local. all you need to do is install all packages to their own folder (eg /usr/local/custom/ruby-1.8.7) and then symlink the binary to /usr/local/bin.

http://github.com/mxcl/homebrew/tree/ is a package manager that tries to do just that

Seems like you might as well do it in opt then, since it is far less common to encapsulate things in folders in local.

Sure you could do something like that, but the OP did not suggest such a practice.

I've often wondered about the difference between /usr/local and /opt. Thank you for posting this.

I have been fighting for hours trying to get the mysql gem installed for Ruby 1.9.1 on snow leopard. If anyone knows some helpful info for getting this to work please help me. I have a thread running at: http://stackoverflow.com/questions/1357997/snow-leopard-ruby...