I'm looking for a php, gpl equivalent to something like Evernote for a research tool, I think these are called note organisers? Most lists I'm finding of Evernote alternatives are desktop based, not online and the few I'm finding in those lists that are compare poorly. It's occurred to me that a wiki is also an equivalent, not sure what the distinction is between the two but I'm looking at Mediawiki and SMW+.

Could somebody recommend a note organiser? Say what (if any) differences are between a note organiser and a wiki? And if a wiki is in fact the same recommend one that might be suitable for using for a research project. Thanks in advance.