Free library management systems

" Are there any good free library managment systems? "

 Rather than simply reproducing something that is done very well elsewhere, please see this comparison of three openSource library management systems.

 http://www.slideshare.net/vimal0212/open-source-library-management-systems

(thanks to Foundry IT for digging out that link)

From checking the Koho website, they recommend a Linux server to run it on, so that requires investment in same, unless you already have a Linux server.

PHPmyLibrary will run on any operating system but does have its own set of requirements.  PHPMyLibrary runs on webserver software.  As with many open source applications of its type, it requires the following to be set up on your server: Apache web server, PHP, MySQl database. 

However, because all of these technologies are essentially web technologies, you could house your library system in the same place you might house a website, so all you would need to do is contact a hosting company, e.g. hostingireland.ie , hosting365 or blacknight and get them to set up a siutable hosting account for you.  That would mean that you could access your system from anywhere with an internet connection.