> The first one is not to try to fix things that are not broken or better, if you want to fix them, only fix the broken pieces and do not try to fix what is clunky but it does, somehow, work as it is intended to. For instance, UTF-8 is a wonderful idea and you need to do that but you can implement that in libraries or subsystems in such a way that you can use it in other operating systems more than create an operating system all around an encoding system.

I disagree 100%. The Plan9 use of Unicode and UTF8 was visionary.

Character set handling was seriously broken on all Unixen in the 1980s. One major problem was the range of character sets available on most hosts which constrained the type of character data applications could handle easily. Another was the plethora of competing, overlapping encodings like EUC-JIS and SJIS or the myriad of ISO-8859 encodings. This required constant mapping (or rather partial mapping) between different layers of the stack with attendant hits on usability, configuration problems, data corruption, etc.

Unicode with UTF-8 storage encoding almost completely solves these problems, the more so as software up and down the stack adopts the same conventions. At least on the projects I worked on then in the DBMS industry we would have gladly taken the hit to upgrade.

[edit] corrected typo