Though GIF is the one of the first image format for animation, and it's been widly used, it seems lost favor recently, mostly because of Flash.

So, I am not planning to make lots of GIFs, instead I will make only a couple limited to the areas GIF is still good enough. Before I show an introductory tutorial for GIF animation using GIMP, I will introduce a good article on GIF animation.

An article on GIF's revival, Aug 12, 2012, from Bits, Digital Diary: How GIFs Became the Perfect Medium for the Olympics

GIFs, those simple, short animated images, should have faded into obsolescence as computers and the images they could handle became faster. They belong in a technology boneyard, decaying and forgotten, with their kindred: laserdiscs, VHS tapes, Zip drives.
But instead, they're having a renaissance, as Ann Friedman at the Poynter Institute and others have noted. Whether they are used to capture a delectable moment on a show like "Mad Men," an epic tumble down a flight of stairs or a bizarre facial expression, they are like the best bits of a conversation or a spectacularly good punch line, on repeat, for your entertainment, forever. They're almost always good for a laugh or two.

One of the biggest innovations in the history of the Internet was the ability to integrate photographs and other illustrations with text on a web page. The illustrations come in the form of bitmap files. A bitmap file simply describes the color of each pixel in the image. To decrease the file size of these bitmap images, several different techniques are used to compress the image data. Typically, Web sites post these sorts of images as either JPEG files or GIF files. Animation is just a series of still images shown in sequence, so the most obvious way to add animation to a Web site is to post a series of bitmap images that the user's browser displays in sequence. This sort of animation, called GIF animation, or GIF89, was the first Web animation to catch on, and it is still very popular today. The main advantages of GIF animation are that it is incredibly simple to work with and it is automatically recognizable to most Web browsers. With a shareware program, such as GIF construction set for Windows or GifBuilder for Macintosh, all you have to do is provide the individual bitmap images that make up the frames of your animation. You then post the file and code the tag for the image, just as you would with an ordinary static GIF. The disadvantage is that you have to keep the animation pretty simple to keep the file size down. After all, each frame is a full bitmap image. Four simple frames transmit very easily to most users, but when you get up to something like 20 frames, your file size could be too big. And you can't even accomplish very much with 20 frames -- the fluid animation we see in movies includes at least 24 still images every second -- so animated GIFs are fairly limited. To create a movie of any substantial length, you have to make pretty big jumps between each frame, which means the animation is not very fluid. - from howstuffworks

This is not Java animation just because it's Java's mascot, Duke. But it's gif animation!! You may want to check Gif Animation Tutorial to see how I made it using GIMP.

Gif related articles

Stilly

Read an article "Stilly Is A One-Button GIF Maker For iPhone That's Even Easier Than Vine from TechCrunch May 2013.

Like GIFs? Tumblr? Got an iPhone? $2.00? Okay, good, then you'll probably like this new app called Stilly, which is either the most ridiculous thing ever or the most fun you're going to have all weekend. The app, in a nutshell, turns anything you capture with your iPhone's camera into a jiggling, wiggly, color-flashing GIF.

FlipBoard

Flipboard Updates iOS App With GIF Support - Aug, 2013.

Nary a soul on the Internet can resist a good GIF, but Flipboard browsers on iOS devices have been deprived until now. Today Flipboard has hooked up iOS users with GIF support, a feature Android users have long enjoyed.
The update includes support for GIFs within the news feed, as well as some new GIF-centric magazines such as "Just GIF It" (lots of cats and things related to cats), "GIF Pop" (slightly terrifying but pretty awesome), and "GIF Me A Break" (a beautiful collection of artsy GIFs).