I got to know Keith when he started contributing to the Tika open source project at the Apache Software Foundation. His contributions were of high technical quality and it didn't take long before we invited him to join the project team as a committer. Committership at Apache requires not just technical talent but also peer respect and ability to work together in a diverse and highly distributed development community. Keith excelled in all these categories. I feel privileged to have worked with him and look forward to future cooperation in Tika or in other projects.
I have been enormously fortunate to work with Keith on my dnsruby project (https://www.github.com/alexdalitz/dnsruby) over the last few years. Indeed, if it wasn't for Keith's complete dedication to open source and community software, there would currently be no dnsruby project. It was Keith who took the time to ensure that the Verisign usage of the project was contributed back to the community, and who persuaded me to continue the project on github when rubyforge ended. I'm certainly glad that he has, and I'm sure that the people who have totalled over a million dnsruby downloads agree!
Keith has been a tireless and committed member of the team, and his indefatigable determination to make things work, and work better, has been inspirational. It seems that he simply won't let things go, but has always gone the extra mile to ensure that the community are well served - even in the most tedious of circumstances, and out of his personal time.
It's the effort, grit and technical skill of people like Keith that keep the open source community moving forward, and I'm truly indebted to him for this.
I can wholeheartedly recommend Keith - not only for his excellent technical work, but also for his innate character - he has always been a joy to work with, and will consistently see the positive whilst working for the common good. I think that these skills would prove invaluable to any software team or project - it is rare to find such a combination of skill, determination and humility.