TiddlyWiki/tiddlywiki — comment on commit 49e0ead1267c534c63c6c0601da721af1a807376
File: js/Macros.js line 154
By Jermolene:

Using array notation to access characters of a string doesn't work on older versions of IE, so TW uses charAt() instead. See

http://stackoverflow.com/questions/5943726/string-charatx-or-stringx