Format Truevision TGA carries label TGA, which means Truevision Graphics Adapter. It is also called TARGA. This type of files was created by Truevision Inc., which is nowadays part of Avid Technology. It is graphical format targeted on raster graphics. Its advantages are simply editing, no need of compression. It also can support 4 billion colors, unlike PNG that can handle only 16 million color.
Original TGA format was created by AT&T EPICenter in cooperation with Island Graphics Inc. AT&T EPICenter has become Truevision Inc. that was collecting staff of AT&T. Later on this company started updating and upgrading TGA format, which lead to release of its newer version that was independent on hardware and it also contained information about size or depth of picture. Today is used version known as v2.0. To the known advantages belong miniatures shown at certain picture. This version was released in 1989. Then is TGA divided by bit depth of picture. In fact it means that the higher bit depth the more colors it can use. It has been used its 24bit version, which used up to 16 million colors. Later on it was changed to 32bit version.
There is plenty of programs able to open these files. Just to view these files you can download program ALTools that is for free and it has even version for Mac OS. Another application for free is GIMP, which allows to edit these files. Last program is one of the best known graphic editors. And its Adobe Photoshop, which is not for free, but you can download its 30 day trial version. Therefore the best application is GIMP, which allows editing and is also for free.