Install

Put sackspace.el into your load-path (make compile will give you a byte-compiled version). Alternatively install it via package.el from Marmalade
Use (sackspace-mode 1) to enable it

Usage

Backspace : Delete char backwards or delete back Tabstop (or an equivalent number of spaces) [1]

C-Backspace : Delete word backwards (you can customize delete function) [1]

Alt-Backspace : Delete char backwards [1]

Shift-Backspace : Delete all whitespace till non-whitespace char is found.

[1] Takes a numeric argument. You can specify how often it will be executed.

Note: If you use a terminal Emacs C-Backspace and Shift-Backspace are not available.

Supports subword-mode, and paredit-mode. To disable this support change the "honor" customs in M-x customize-group RET sackspace RET.

Supports evil directly by prohibiting edits in non-editing states if evil is enabled.

Within term-mode sacks/whitespace won't work (it will delete the chars from the emacs buffer, but not from the terminal).