Each package, however is only a reader or an output tool. The software vendor makes their money on the encoders and input tools. Adobe's PDF Reader may be downloaded from this site. Portable document format allows you to exchange documents across platforms and across software packages. Roughly 750K. Mathematica Notebook Reader may be downloaded from this site.
Wolfram research produces software to manipulate math symbols and perform numeric analysis.
The results can be displayed and animated with this tool. Roughly 450K. Compression Software for many machine types may be downloaded from this site. Frequently, files become extremely sluggish to transmit over low bandwidth lines. Software found here helps to compress and expand files to facilitate transmission. Program sizes will vary by machine but are roughly 350K. RealAudio Sound Player may be downloaded from this site.