a downloadable software marketplace......
I would use H&R Block software. It is affordable, cheap and easy to understand. Go to the website and find the software there.
A good open source IDE for C++ would be Code::Blocks or Notepad++.
Wiki and Google. Be specific about what you need from what software.
You can find a good Presentation Website or Software at powtoon.com.
Reviews for CRM software abound online and come in all different varieties. One good source you can visit to look at reviews for CRM software can be found at http://www.comparecrm.com/
Open Source software is software which is free and has source open to anyone, meaning that anyone with skills can modify and improve it, and everyone can do anything he wants with it. Good examples would be: Linux Firefox Open Office.org Thunderbird Pidgin
Wikipedia is always a good source of information. Try http://en.wikipedia.org/wiki/Cafeteria It should have some good facts.
The best place to find out about a good source for DAB radio stations, would be to speak with a disc jockey. They would have a lot of different input about DAB radio stations.
A good source to find product information for Furuno products would be the Furuno product manufacturer's website. Reviews can be seen on Amazon and Nextag websites.
A good place to find issue management software is on the 'Atlassian' website where their software package can be downloaded. Another good place is 'MetricStream'.
Network controllers are usually built into Windows software. Other good places to find this are on either File Hippo or Download. Tom's Hardware is another good source for info.
There are tons of websites out there to help you find more information on bookkeeping software, i would check out quick books online, it is a good website to help