I've been using GetSimpleCMS for a number of years now, but there have been some php issues over the past year or so
Recently tho, some of the GetSimple community have started working on a community branch called Get Simple CMS Community Edition
And I have to say they have done a wonderful job updating GetSimple and improving it.
The Community Edition added a ton of features, including a new admin interface, adding plugins from the console and a lot more
Check it out here GetSimple CMS CE
John