Nanny is an easy way to control what your kids are doing in the computer. You can limit how much time a day each one of them is browsing the web, chatting or doing email. You can also decide at which times of the day they can surf the net, email or chatting.
Nanny can also filters what web content for each specified users, so you can block all undesirable webs for your kids with ease of mind, no more worries!
Install Nanny on Ubuntu Linux:
Open a terminal from Applications > Accessories > Terminal, and type following commands ...
sudo add-apt-repository ppa:guadalinex-members/ppaAfter installation, you’ll find an entry for Nanny in System > Administration > Parental Control. There’ll also be an entry for the Blacklists admin tool in System > Administration > Blacklists.
sudo apt-get install nanny
If you want to control access for the particular websites, you can easily do that by specifying the lists of allowed and blocked sites, for this you need to 'enable web filtering' box in the web browser tab and click 'configure'. for this you can also download the list of blacklist sites from here and provide it to the nanny.
Experience Linux users can also try privoxy or timekpr or DansGuardian along with content caching using squid.