How dose impress work compared to power point I have about 5 or more people who need power-point for their kids home work assignments , but money is tight so I would like to go with the shareware if it will work for them.
IMO, since it's free I say try OpenOffice to see if it meets their needs. It has come a long way.
Microsoft Office is the standard and is generally easier to use. Since it's for the kids they should qualify for the Student and Teacher edition which is well priced at $125 from Newegg. It included Word, Excel, Outlook, and Powerpoint.
if it was me, i'd go for the openoffice program. it does everything office can do, or at least everything that i use it for. only downside is that it cant use some microsoft proprietary features, although it usually wont be a problem if it's for kids. downside of openoffice though, that the programs use more ram. but for ~$100-$300 less as opposed to office, i'd take it.
MS-Office has more bells and whistles, animation, sound, and handles embedded video better, but to be honest, if somebody is using all those things on their presentation, the presentation will suck out loud. If you want real professional quality presentations, either will work fine. One really nice thing about openoffice, is the PDFs it can create.
Considering that OpenOffice is free, I say try it, and they can always spend money on MS-Office later. If they get MS-Office, then have OpenOffice installed too, because they don't interfere with each other.