Replacement - openoffice.org - replaces MS Office suit of applications with very small foot print. - test it and you shall know. It has word, excel and powerpoint replacements. File format can be any ms office version or openoffice's own xml compressed form. 1 mb file typically saves to 80 kb in my experience.
Drawing module is very extensive - MS should be doing catch up for many years to come. Please note - MS offering is very good but Openoffice is better. Small size - 60 mb, under 200 mb full install. Best of all it is FREE. and available for nearly all operating systems. It also has a built in flash generator for presentations and pdf generator for all applications.
Free PDF Generator
You need 2 applications for this operation. Ghostscript and FreePDFXP. I have given same link as you get the downlink for both from the freepdfxp site. this also allows you to encrypt your pdf files.
Ogg Vorbis. Yes - that is the name - Ogg Vorbis is a completely open, patent-free, professional audio encoding and streaming technology with all the benefits of Open Source.
If you think this is bad - a FREE player "Oggplay" is also available for Symbian OS - used in mobile phones. So if you use Nokia 6600, Siemens SX-1 or any similar product - you can download it free and play fantastic Ogg files [about 1/3rd the size of a good MP3 compress + it is free]. To put it in perspective a 3 hour recording gives a digital quality compress of only 60 mb. A similar compress on MP3 would be about 180 mb, in WMA windows media about 80 to 90 mb. So a 512 mb MMC [a flash memory card used in smart phones and cameras etc] would give you 24 hours play time - though at lower bit rates you can stretch that.
XviD. Does DivX ring a bell? XviD is a continuation of Project Mayo and aims to develop a high quality open-source MPEG-4 codec. As you may already know, XviD comes from the same open-source project that was the basis for DivX 4.x/5.x, but instead of going all commercial, XviD remains open-source. The quality of the codec is extremely good, and encoding speed is very fast as well, a full size hindi movie DVD encodes to about 350 mb - fantastic image display.
What ever is listed by me has actually been tested by me and used regularly.