Just to underscore your point: I'm an engineer at Wikimedia, and I worked quite closely with Brett, the author of the blog post. As a small nonprofit operating a very popular site, we're accustomed to being approached by salespeople camouflaged as altruists, and over the years we've developed a pretty good nose for that sort of thing. The people on the HHVM team with whom I interacted were palpably genuine and nice, helping us out at odd hours of the night, and asking for absolutely nothing in return. They're wonderful people, full stop.

> so they're not the only ones who want to maintain it

Being completely unaffiliated with Facebook, I think this still counts as 'greater good' for many.

Sure. I'm just saying that they have business motives to do so, it is not merely out of the kindness of their hearts. Though I am sure it is also partly the latter, they have some wonderful engineers. :)

As far as I'm aware, HHVM isn't something that FB is charging for. If that's true, what's the business interest?

The same one I mentioned before: getting other people to use it benefits them, as other people will help maintain it because they also have a stakehold in its success. It's a huge project to maintain.

If you define it that way then there's almost nothing in the world that would categorize as altruism. Helping kids in Africa? It's only to make yourself feel good. Helping that fallen granny get up? It's to make yourself look good in front of others. Etc. If you go that far, both egoism and altruism will have completely lost their meanings.

>Helping kids in Africa? It's only to make yourself feel good. Helping that fallen granny get up? It's to make yourself look good in front of others.

Exactly! Of course we do things to make ourselves feel good. And since helping other people makes us feel good, why shouldn't we be honest about our motives? It's win-win.

Is it a huge project to maintain? I thought the first HipHop implementation was a 2-person side project. Relative to FB's size, does it matter even if they had to put 10 people on it?

Originally, yes, but it's grown since then, and bear in mind that it is critical infrastructure that Facebook are now completely dependant on.

The other business interest is... as it gets more adopted, more people will know the ins and outs, and the talent pool for them to pick from will grow.

More other businesses using it also makes it harder for people to make the argument against it as "it's just a Facebook thing"

Yes. It's probably hard to hire developers if they must program in an obscure internal-only dialect of PHP (Hack).

That comment got downvoted to -1! I'm not saying Hack is obscure and used only by Facebook - but it would have been had Facebook not open-sourced HHVM and tried to promote its use.

It's not that obscure. Anyone with an ounce of experience in PHP can start writing solid Hack on day one. And that would still be true even if Hack were never seen in the wild.

Unless you think it's hard changing the open tag from <?php to <?hh :p

I'd be surprised if anything-PHP is a bonus to hiring. Most likely people work on it despite of PHP, not because of it.

No, many people work on it because of PHP - because of the speed and flexibility of dev with it.

I've done PHP, some Ruby, some .NET, Java and more - coming back to PHP is often fun and a breath of fresh air. Nothing's perfect.

Um, this is literally the open source process. This is how it's supposed to work.

http://catb.org/esr/writings/cathedral-bazaar/

That is even better! Because that creates incentives to continue supporting it.

In the last several years I've spoken to libertarians, conservatives, progressives, various schools of economics etc. It's become clear to me that when platforms are free, more wealth is created. When Netscape open sourced their codebase, we got Firefox and WebKit. Linux, Webkit, WikiWikiWeb, Git, in fact all those image formats you can display without paying royalties or risking getting sued, obviously led to more wealth creation than proprietary siloed codebases. Eventually even MS opensourced their platform, after years of copying by Mono.

I think a better example would be Btrfs. Facebook hired the lead Btrfs devs and they are still contributing to Btrfs development. And this is because Facebook is very interested in Btrfs themselves.