Back in the early days of personal computing, if you wanted a computer to do something, you typed a command on the keyboard. It was quick and direct but also off-putting for millions.

You had to learn a complex language and enter commands in just the right way. And the commands were different for different programs.

Then, Apple, building on work done by Xerox, introduced computer systems that you could control without typed commands. Instead, you used a mouse to click on icons and menus. Microsoft soon followed with Windows, and today all consumer personal computers work this way, out of the box.

However, for some people, especially fast touch typists, removing a hand from the keyboard to use the mouse is annoying.

Now there’s a new software system that allows people to use keyboard commands for common tasks. The commands needn’t be memorized, because they are entered in plain English. And they stay the same no matter what program you’re using.

The system is named Enso, and it comes from a small Chicago company called Humanized Inc.

There are two initial Enso products, which can be downloaded at humanized.com. One, called Enso Launcher, allows you to launch programs and switch among windows via typed commands. The other, called Enso Words, allows you to do spell-checking, even when the program you’re using doesn’t include that capability, and to look up the meaning of words. Both products also include a simple calculator and the ability to launch Google searches.

Enso is dead simple to use. You just hold down the Caps Lock key and type an Enso command, which is displayed in a translucent overlay. Once the command is typed, you simply release the Caps Lock key to activate it, and the overlay disappears. If you type fast, it all happens in a flash.

For instance, to launch the Firefox Web browser, you just hold down the Caps Lock key and type “open firefox.” To look up the meaning of the word “proclivity,” you just hold down the Caps Lock key and type “define proclivity.” You lose the normal use of the Caps Lock key.

Enso Launcher costs $25, and Enso Words costs $40. For now, they work only on Windows XP – not the new Windows Vista or the Macintosh.

Enso Launcher is simpler and seems more useful than Enso Words, partly because so many programs now have spell-checking. I wasn’t able to test the calculator and Google features, which were late additions.

Enso commands are even faster to enter than they might seem. The program auto-completes the commands as you start typing, and it provides the likely choices in its translucent overlay, which you can navigate with your arrow keys. Suppose you want to open the Windows calculator program. You hold down Caps Lock and type “open calc,” and Enso Launcher completes the suggested command “open calculator.” Even before that, when you typed “open cal,” the drop-down list appeared, with “open calculator” at the top.

In addition to “open,” Enso Launcher also has a command called “go,” which can take you to any open window or tab in a Web browser. While I was writing this paragraph in Microsoft Word, I held down the Caps Lock key and typed “go patriots” to get to the New England Patriots Web site, which I had open in a tab in Firefox.

There are also commands for quitting programs and for closing, maximizing and minimizing windows.

In Enso Words, you can select any text in any program, then hold down Caps Lock and type “spellcheck.” Any misspelled words are highlighted, and you can correct them by either retyping or choosing from a list of suggestions.

This spell-checker is clumsier than the built-in checkers in programs such as Microsoft Word, but it might be handy in instant-messaging programs or in other Web pages where spell-checking isn’t built in.

The “define” command also brings up a thesaurus, as well as dictionary definitions.

Enso isn’t for everyone. If you’re fine with the mouse, menus and icons, you may not want it. But for keyboard addicts, it could be a blast from the past.

Walter Mossberg writes about personal technology for The Wall Street Journal.