Unicode in source code can come with unwanted consequences. Tooling might be required.

Ever wondered how to make a code formatter? This post does a good job showing the main problems you might encounter. The impact of Unicode is especially funny. Very interesting stuff.

Very nice primer on how Unicode works. Definitely a must read and a good starting point. Definitely highlights properly some of the difficulties we need to deal with now and talks about the normalization forms.

An excellent explanation of the Unicode standard, complete with a bit of history. This is a good resource.