You may additionally have observed that “programmed” and “programming” stand as an exception to the standard tendency for final consonant doubling to occur in -syllable words simplest when the second one syllable is careworn (as an example, we double the very last r in occurring however now not in harboring). I Programing use “tendency” guardedly right here: Various other exceptions to this tendency exist, and proponents can with no trouble be determined for both side in the debate over such unsettled forms as labeling/labelling and leveling/levelling.
Anyway, in U.S. English—or as an alternative, in the representation of U.S. spelling options provided within the Merriam-Webster Collegiate Dictionary series—the preliminary desire with reference to the -ed and -ing kinds of the verb program was for no consonant doubling. The debut of software as a verb came in the Collegiate Dictionary’s Programing Sixth Edition (1949):
application v.t. PROGRAMED or PROGRAMMED; PROGRAMING or PROGRAMMING. Also programme. To set up or grant a application of or for; to enter in a program; to invoice.
I trust that the impetus for this desire was the syllable pressure take a look at; clearly that would be steady with the fact that programmatic (in which the best strain falls at the 0.33 syllable) is listed with handiest the double-m spelling.
Anyway, real utilization led to a reversal of the Sixth Collegiate’s order of preference. The Seventh Collegiate (1963) offers the double-m spellings first:
program also programme vt programmed or programed; programming or programing 1 a : to set up or furnisha program of or for : BILL b : to go into in a program 2 : to training session a series of operations to be finished by way of (as an electronic computer) — programmer
Notice that programer isn’t always an alternative right here. It is quite feasible that, going ahead, the significant role of computers as the gadgets of programming made the spelling alternatives of laptop engineers and builders mainly great. In any case, whilst the pc-associated definition of the verb software arrived within the dictionary, the spelling desire flipped.
It flipped, however programed and programing did not vanish altogether. In reality the ones spellings nevertheless seem as opportunity spellings within the Eleventh Collegiate (2003). But the weight of real-world utilization is overwhelmingly in choose of doubling the m, as this Ngram chart of programed (blue line) and programing (crimson line) as opposed to programmed (green line) and programming (yellow line) for the length 1930–2005 shows:
And here’s how the early years (1930–1965) of the competition appearance, for nearer assessment:
This chart strongly suggests that programed and programing by no means loved a widespread gain in published writing over their double-m counterparts, so perhaps Merriam-Webster have been backing the wrong horses all along. In any case, that dictionary nonetheless honors the uncommon single-m spellings with the aid of treating them as complete-fledged variants, as does the American Heritage Dictionary of the English Language (that is the number one dictionary depended on by means of Microsoft Word)—and that’s why your spelling checker, by means of default, does not flag it.