Evernote  is a remember-everything notebook app beloved by obsessive developers, project managers, and generally forgetful creatives everywhere. This week the company launched a revamped Windows version, which will bring it up to speed with the slick version for Mac. If you're a PC goon and you haven't tried Evernote, this is your best excuse.
Why? Because Evernote on all platforms is a stellar example of what software can (and hopefully will) become in the next three years. Not only does the company make versions of its notebook software for Mac and Windows, but also for iPhone, Blackberry, and Palm (with Android coming soon, CEO Phil Libin says.) That means that pretty much every device you encounter will have a fully synced collection of your notes, URLs, audio reminders, video reminders, screen-grabs--all the miscellania that gets buried in your Documents folder.
If you're without your hardware, there's a Web account where you can access all your junk. But getting access is only half the story. You can also send things into your Evernote notebooks in a startling array of Web 3-ish ways: send an email to your special account address, Tweet a note or URL to @myen, or use the bookmarklet to send the contents of a website. If you work frequently with paper documents, there are several services that will scan your documents into Evernote; just drop them in the mail. Get a blot of business cards? Snap photos of them, send to Evernote, and it reads them; search a name, and it'll pull up the image. It's a fully accessible ecosystem: iterative, open, extensible, and flexible.
Incredibly, Evernote also has its own open API , or application programming interface, so you can insinuate Evernote functions into just about any desktop, mobile or Web app you want to build. You can also script for Evernote in Windows and Mac OS. Several popular note-taking apps like JotNot have already done as much.
The most amazing part? Evernote is entirely free until you reach a 40MB threshold of monthly syncing--an impossibly high bar for text, links, notes, snapshots, and so on. (The New York Times recently marveled at the "freemium" business model here .) If you're a Mac fanatic and you want a slightly more ascetic, harcore-nerd version of the Evernote concept, check out VoodooPad , by Seattle developer FlyingMeat , maker of the popular image editor Acorn.