The Irish Free Software Organisation (or IFSO) is a member organisation based in the Republic of Ireland which works to promote the use of free software in Ireland, and oppose legal or political developments which would interfere with the use or development of Free Software.
It is an associate organization of Free Software Foundation Europe (FSFE), with which it continues to maintain close ties.
IFSO was founded in January 2004 with the aims of promoting and protecting the freedom to study, modify and redistribute Free Software.
IFSO was founded as an extension of work on the EU Software Patents directive being performed by an ad hoc group, who perceived a threat to the Free Software community from that legislation. The organisation was intended to foster the Free Software community in Ireland, and to continue this legal and political work in a coherent manner.
Although IFSO is a membership organisation, with a committee to provide structure, formal membership is considered less important than an individual's willingness to participate and take initiative. IFSO frequently collaborates with related organisations.