11. A system, comprising: one or more computers; a display device; one or more storage devices; a computer program product on the one or more storage devices, the computer program product operable to cause the one or more computers to perform operations comprising: receive text coding information identifying each of a plurality of characters of text represented by the non-coded representation; based on the text coding information, generate a coded representation that: specifies, for each of the plurality of characters of text represented by the non-coded representation, a respective code value based on a character encoding, the code value selected to represent the respective character of text, and associates a particular glyph from a collection of glyphs with each of the code values specified for the plurality of characters of text, the particular glyph selected independently of any relation to the respective character of text, the collection of glyphs being insufficient to semantically represent the plurality of characters of text; associate the coded representation with the non-coded representation, wherein a code value of one of the plurality of characters of text is associated with one or more positions in a visual representation of the non-coded representation; display the visual representation of the non-coded representation; search the coded representation to find a coded character sequence that includes one or more characters at a location in the coded representation; and highlight, in the displayed visual representation of the non-coded representation, the portion of the non-coded visual representation associated with the coded character sequence at the location in the coded representation.
11. A system, comprising: one or more computers; a display device; one or more storage devices; a computer program product on the one or more storage devices, the computer program product operable to cause the one or more computers to perform operations comprising: receive text coding information identifying each of a plurality of characters of text represented by the non-coded representation; based on the text coding information, generate a coded representation that: specifies, for each of the plurality of characters of text represented by the non-coded representation, a respective code value based on a character encoding, the code value selected to represent the respective character of text, and associates a particular glyph from a collection of glyphs with each of the code values specified for the plurality of characters of text, the particular glyph selected independently of any relation to the respective character of text, the collection of glyphs being insufficient to semantically represent the plurality of characters of text; associate the coded representation with the non-coded representation, wherein a code value of one of the plurality of characters of text is associated with one or more positions in a visual representation of the non-coded representation; display the visual representation of the non-coded representation; search the coded representation to find a coded character sequence that includes one or more characters at a location in the coded representation; and highlight, in the displayed visual representation of the non-coded representation, the portion of the non-coded visual representation associated with the coded character sequence at the location in the coded representation. 12. The system of claim 11 , wherein: the collection of glyphs consists of a single glyph.