Adobe are the makers of Photoshop, InDesign, Illustrator, GoLive! and a number of other professional graphic tools – stalwarts of the graphic design community. Macromedia is definitely best known for Flash and Dreamweaver, but also creates Freehand, Fireworks and Contribute. Several of the tools from Adobe and Macromedia overlap in purpose however, so it will be interesting to see which products continue to be developed and which products will have their features merged or eliminated.
The merger still apparently requires shareholder approval. Source: MacWorld.