DocPad is a free alternative to Notepad.
Although it fills the same role, plain text editing, it offers an arsenal of time-saving tools: block indent/unindent, bookmarking, case conversion, encoding conversion, file backups, file history, jump to line/offset, keyboard macros, print preview, search and replace, skinnable interface, spell checking, statistics, text to speech, and much more.
DocPad's Tabbed Document Interface allows you to open multiple files.
It also includes a built-in calculator, calendar, and character map.
DocPad is pure freeware for Windows.
It does not display advertisements and does not install third party apps.