The "Fail Whale," a relic of a more volatile time. Source: Twitter.

In 2010, Twitter was so obsessed with preventing the sorts of outages that revealed the dreaded (but also lovable) "Fail Whale" that one of its engineers took to the company's blog to describe, technically, what was bringing the social network to its knees.

"To be precise, we show this error message when a request would wait for more than a few seconds before resources become available to process it. So rather than make users wait forever, we "throw away" their requests by displaying an error," former Twitter engineer Ed Ceaser wrote at the time.

Think of it as arriving at your favorite lunch destination only to find no one available to take your order.

Now, as Twitter nears an IPO, the "Fail Whale" has gone extinct. According to Pingdom, the microblogger's site has been 100% available in five out of the past six months.

Impressed? You should be, given Twitter's history. But it's also important to note that Twitter isn't the only one to have made uptime improvements. Every company that's bet at least some of its business on the reliability of the Internet has made structural improvements in recent years, some of which might even seem crazy.

Take Facebook (META -4.13%), Twitter's closest peer and one of the pioneers of the Open Compute Project. The guiding idea is to rethink the elements of hardware that governs a data center and then share findings in hopes of making entire data centers -- the lifeblood of Internet services such as Twitter and Facebook -- more efficient and effective.

Google has invested in solar power to help reduce emissions and its data centers' dependence on the grid. Rackspace Hosting has transitioned its entire infrastructure to an open source platform called OpenStack. Amazon.com has introduced a new Service Level Agreement for its online Relational Database Service that apparently guarantees 99.95% uptime.

These sorts of structural improvements (or gambits, in Amazon's case) may help to explain why Facebook didn't simply crumble earlier this week when problems with its Payments system prevented users from posting status updates and accessing other features. By necessity, the social network's foundation is firmer today than it was a few years ago.

Twitter's vastly improved uptime says the same about its infrastructure -- not to mention its ability to deliver advanced products and services in a timely, profitable manner. CEO Dick Costolo seems to have timed this IPO perfectly.

Do you agree? Will you buy Twitter's planned IPO? When is the last time you spotted the "Fail Whale"? Let us know what you think in the comments box below.