Perens left OSI in 1999, a year after co-founding it. In February 1999 in an email to the Debian developers mailing list he explained his decision and stated that, though "most hackers know that Free Software and Open Source are just two words for the same thing", the success of "open source" as a marketing term had "de-emphasized the importance of the freedoms involved in Free Software"; he added, "It's time for us to fix that." He stated his regret that OSI co-founder Eric Raymond "seems to be losing his free software focus." But in the following 2000s he spoke about Open source again. Perens presently volunteers as the Open Source Initiative's representative to the European Technical Standards Institute ("ETSI"), and is a frequent participant in review of license texts submitted to OSI for certification as Open Source licenses.