GreenNet is a not-for-profit initiative based in London, England, that supports what it terms the "progressive community working for peace, the environment, gender equality and social justice, through the use of Information Communication Technologies (ICTs)."
"ISP, unlike others"
GreenNet was founded by Mitra Ardron in 1985. It calls itself an ISP that is "unlike many other Internet Service Providers, is geared to the needs of non-profit organisations, activists and people working for social change." 
It supports groups working for peace, human rights and the environment, through the use of Information and Communication Technology (ICT).
GreenNet Educational Trust
In 1994, GreenNet set up the GreenNet Educational Trust, a registered charity, which receives profits from GreenNet activities. The Trust's goal is to support and promote the use of ICTs. GreenNet is a founding member of the Association for Progressive Communications (APC).
GreenNet says it "began as a cheap and effective way for environmental activists to communicate."  In 1989, it started collaborating and exchanging information with similar networks in other countries.
International gateway to Africa and Asia
Since 1987, GreenNet played the role of providing an international gateway for small networks in Africa and Asia. This made possible the exchange of email between the internet and 52 networks in Africa and Asia.
GreenNet has been built "specifically to support small to medium sized organisations, in particular, activists and NGOs." It also hosts web pages for social and activist organisations focused on peace, economic and social justice, human rights and environmental sustainability.
Right to communicate
GreenNet has been focussing to deliver the alternate and campaign network with "content driven websites", based on the Drupal content management system.
2013 DDoS Attack - Zimbabwean Elections
Beginning at 10.15 BST on Thursday 1 August 2013 APC, and consequently Green Net, suffered an extensive DDoS attack.  The attack was later described as a "DNS reflection attack" also known as a spoofed attack Several sources linked the attack to the Zimbabwe Elections. GreenNet's services were not fully operational again until 10.30 BST on Thursday 7 August. On the 9th of August there was a second attack, which, while affecting some systems, allowed GreenNet to discover the site which was being targeted. GreenNetISP stated on Twitter that they did not yet have permission to announce the name of the site.