coder: n. (computing) programmer
The term "coder" refers, in various circles complimentarily, derogatorily, or non-perjoratively, to a computer programmer.
"Coder" versus nothing: In its non-perjorative sense, "coder" is simply a jargon synonym for "programmer."
"Coder" versus "Programmer": In its derogatory sense, "coder" is contrasted with "programmer" to indicate a lower level of programming skill, usually than the user of the term. This programmer/coder dichotomy would be parallel to the reporter/hack dichotomy in journalism, and is generally used by vocational programmers to refer to non-vocational or skilless vocational programmers.
"Coder" versus "Scripter": In its complimentary sense, "coder" is contrasted with "scripter" to indicate a higher level of programming skill, especially in using "real" programming languages1 (generally with specific reference to compiled versus interpreted languages). A "coder" then is an upper-level member of the in-group, while a "scripter"2 may be part of the in-group, but of lower caste. In this case, "coder" indicates a member of the in-group, while "scripter" a wanna-be. (see Coding Versus Scripting)
It is interesting to note that this term is only infrequently (and by the more pedantic) used to set up a continuum of expertise — though a range from user→scripter→coder→programmer→demigod→god might seem obvious. Rather, it is generally an inclusive term: when used derogatorily, it embraces all lower skill levels, and when used complimentarily, all higher skill levels. Even when used non-perjoratively, it will usually embrace all skill levels rather than any particular level.
1. The distinction, for whatever reason, has more to do with compilation methodology than language complexity or power: for instance, the author thinks and dreams in ANSI C in all its glory, without any "helpful" utility libraries other than those of his own devising, but can't seem to wrap his brain around Perl, and in fact has profound respect for Perl gods such as Rael Dornfest.
2. Occasionally, "scripter" will be used to indicate a "script kiddie," or a user of pre-written scripts and programs who considers himself to be a "l33t hax0r" by virtue of minor modifications he is capable of making, and illiteracies he is capable of committing.