ADVANTAGES OF FOSS
1. It is free of charge as it can be downloaded from the internet.
2. Can be modified because its code is supposed to be freely available.
3. OpenOffice.org with all its quirks is far better than Microsoft Office for those who cannot afford Microsoft Office and wouldn't have such a product it it were not for the OpenOffice.org providers.
DISADVANTAGES OF FOSS
1. Most open source are not reliable.
2. No support for exist open source software.
ADVANTAGES OF COMMERCIAL SOFTWARE
1. It is liscenced so the company can install and provide maintenance for you.
2. Your work is secured.
DISADVANTAGES OF COMMERCIAL SOFTWARE
1. It is expensive.
2. It cannot be altered and redistribute.