IANA-MIME-Types

node module with enumerations of MIME types.

var mime = require('iana-mime-types');

console.log(mime.Application.JSON);               //  "application/json"
console.log(mime.Audio.MPEG4_GENERIC);            //  "audio/mpeg4-generic"
console.log(mime.Image.VND_FUJIXEROX_EDMICS_MMR); //  "image/vnd.fujixerox.edmics-mmr"
console.log(mime.Message.SIP);                    //  "message/sip"
console.log(mime.Model.IGES);                     //  "model/iges"
console.log(mime.Multipart.FORM_DATA);            //  "multipart/form-data"
console.log(mime.Text.JAVASCRIPT);                //  "text/javascript"
console.log(mime.Video.1D_INTERLEAVED_PARITYFEC); //  "video/1d-interleaved-parityfec"

Enums generated from http://www.iana.org/assignments/media-types/media-types.xhtml