How can I have the three source-code symbols _ < > produce themselves (_ < >) in the typeset output by default?

Question

I use LaTeX to take quick notes about my programming work. I have a couple of frustrations:

• I need to use underscore a lot because of variables named with underscores. However, I have to escape each one of them "\_", thus making my notes less readable on the markup side.
• I commonly want to use "<" and ">" symbols - why oh why are the default representations of these symbols "¿" and "¡"?

Is there anyway I can alter LaTeX so that "_", "<", and ">" literally typeset as "_", "<", and ">"?

Answer 1

There are canonical ways to fix both of these problems. For the underscore:

\usepackage{underscore}

For the rendering of < and >:

\usepackage[T1]{fontenc}
\usepackage{lmodern}

Answer 2

FWIW, since the last month \nonknuthmode is default in ConTeXt. What this means is _, ^, and & work in text mode. So, the following is a valid input:

\starttext
under_score car^et & ampersand work in text mode, and have their 
usual meaning in math mode
\startformula
  x_a^b = \cases{ 0 & a < b \cr 1 & a \ge b }
\stopformula
\stoptext

Answer 3

An obligatory ConTeXt answer (plus Aditya's :)), using \asciimode will make all special characters "un-special" except \, { and }:

\starttext
\asciimode
$ % & _ # ^ ~ | < >
\{ \} \backslash
\stoptext

Answer 4

Building on (I do that a lot, lately) Roflcoptr suggestion of using \textgreater and \textless, you can do

\catcode`\<\active
\catcode`\>\active
\let<\textgreater
\let>\textless
\catcode`\_\active
\let_\_

I am assuming that you are not using _ in maths as well. Otherwise, try

\begingroup
\lccode`\~`\_
\lowercase{\endgroup
  \def~{\ifmmode\expandafter_\else\expandafter\_\fi}}
\catcode`\_\active

instead of \catcode... \let_\_. EDIT: note the different placement of \catcode....