I haven't heard of the "Triad". But I have got PHP installed on a few Unix / Linux servers I use. It's straightforward to set up on a server, although usually you just need to tick a box when you order the server.
As regards a development environment, I use either TextPad or Dreamweaver depending on the complexity of the scripting.
In a previous job I did a lot of ASP scripting and found it a right pain in the butt. It was confusing as folks swapped jscript, vbscript and javascript all in .asp files. The first job in any maintencance task was to work out which language was being used!
That job also required me to use Visual Interdev which caused me to remove many hairs as it hogged my resources and took over my network connection just to upload files. It wouldn't even "play nice" with other M$oft products. I really hated it.
And don't even get me started on Front Page!!
But that's just my opinion. In your life, it shouldn't count for much. It seems like you're ready to give PHP a chance. So, forget the comparisons for now. Just get PHP running on your server - ask your sysadmin if you have one. All you need on your PC is a text editor. FTP your "hello world" script to your server and start from there.
Give it as much time as you can for a week or two. That will give you enough time to decide if PHP is for you.
Best of luck,
Jack
