Alex King has recently suggested that we have an about:config for WordPress. When I first thought this I thought “great!” because we’ve had this for several versions now: if you browse to options.php directly you can edit any option in the database, even those that have no UI because they’re from plugins or just something we don’t expose.

However after several comments pointed this out Alex began clarifying his request, some of it isn’t entirely clear to me (I would never want to go back to storing configuration in files, that was a nightmare we eliminated in 1.0), but the main gist is not merely exposing an interface to the options we have, but rather adding many more options to the code to allow for more than one way for some core parts of WordPress to work.

With that clarification, I think it’s pretty safe to say that something like that will probably never be incorporated.
Options have several costs, which is why we avoid them fairly religiously in WordPress. The most obvious cost is UI clutter — everyone wants their 15 pixels of fame and configuration screens quickly devolve into pages of utterly confusing junk no one understands or cares about.

A very closely related problem is user frustration. With WordPress we’re trying to make publishing to the web as effortless as humanly possible, and one part of this is taking care of a thousand little details that really shouldn’t ever cross your mind — if we’re doing our job right. One common reason for the proliferation of options in open source software is that (news flash) people often disagree about how things should be done, often violently and vocally in threads that can drag on for weeks on development mailing lists. (It is frustrating for many people that these option flame wars draw more discussion than useful topics or questions.) Few like fighting about things, and project leaders pull the proverbial car to the side of the road and declare “Screw it! We’ll do both!” To satisfy a handful of developers a burden is put on countless users.

I try to build everything imagining I have a million users. (Someday!) Small things add up — if there is an option in the interface that people have to think about for only 2 seconds (which is probably low) across a million users that’s 23 days (555 hours) of time lost to the world! (Call centers track efficiency per second because of similar constraints. Small things add up.)

Alex’s hidden options don’t trigger either of these by definition. However there is a third hidden cost: as the number of options increases it becomes difficult (or even impossible) to test for all possible combinations of how the options may interact in different enviroments. This also makes support a real bear. Costs go up, bugs increase.

This is why we say no by default to pretty much every suggested option, and we do our best to remove the ones that have built up over the years. (I just axed a whole panel earlier tonight.)

All that said, hard-core developers often need flexibility in the system to expand WordPress to things we’ve never even imagined, and that’s where our plugin system comes in. While we often say no to new options, we rarely ever shoot down a suggested extension to our plugin API. The beauty of this is it allows for near-infinite flexibility in how you interact with the program (there are some amazing plugins out there) while still keeping the core light, clean, stable, and fast. It also makes support relatively painless: “Does it work when you deactivate the plugin?” When someone says they want to do X and it should be core because it can’t be a plugin, 9 times out of 10 I see that as a plugin API bug, not a core bug.

In summation: Don’t waste your users’ time like I just wasted yours with this essay and be mindful of hidden costs. If I had a few extra hours I would edit and cut most of it out. (Good thing I don’t have a million readers.)