I’ve always been bad at leaving.

Today’s my last day at Mozilla (as a full time employee – I’ll continue to be on the Board of Directors), so I wanted to write down a bit of what I’m feeling as I get ready to go in to work. I’m writing this partly so that I can remember what it feels like – I’m finding that it’s quite an emotional time for me – and partly because I haven’t seen much like this around the web, on other people’s blogs.

Schrep likes to joke that of all job skills, I’m worst at quitting, and he always feels bad when he makes that joke, but he’s absolutely right, of course. It takes me a long time to transition. At Reactivity, I transitioned out over 4 months at the end of 2004; at Mozilla, it’s been very nearly a year since I first talked with Mitchell about moving on.

There are reasons for that, of course – it took a bit of time to organize our plans and the organization to be able to get through a transition, and we did a retained search in a relatively speedy 5 1/2 months.

But for me it was a basic equation: I really, really care about Mozilla, and, given the context that I was ready to move to my next thing, I wanted to do whatever I could to make sure that we’d get through the transition stronger than ever. I’ve been extremely fortunate to have the support and patience of both Mozilla and Greylock during this period – and it’s let us change in a way that I think has been very stable and should be good for the future.

It’s already obvious that Gary’s going to be an ouststanding CEO and team member for Mozilla – he’s already a great culture fit, asking questions that cut to the heart of things, and providing clear insights. He’s going to be great. Firefox 4, which is right around the corner, is an incredibly terrific product, both on desktop and mobile, that I think it validates our slow transition approach for the year. And we’ve got so many things coming from our product groups and labs that I’m certain next year will be transformative for the project, the organization, and the whole web.

As you might imagine, hiring a replacement for yourself is a particularly self-centered and self-reflective experience. For me, it caused me to spend a lot of time thinking about what I did well, what I screwed up, how the organization had changed over the years, how I’d changed over the years. It’s taught me a bunch about myself and what I care about, and how I want to live my work life in the future.

I wrote about leaving back when we first announced the CEO search, and all of that is even truer now. I’m proud of what we’ve done together at Mozilla, proud of how we’ve changed the world. I’ve got a deep gratitude to the whole community that let me come in and gave me the support to make my own mark on the project. And I’m really, really excited to watch the whole project change the world in new and amazing ways in the years to come.