Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_1574968_1 (viewer VARCHAR, language VARCHAR)
### Question:
Which viewers have the language of troff (typesetter runoff) , groff (gnu runoff)?
### Answer:
SELECT viewer FROM table_1574968_1 WHERE language = "troff (typesetter runoff) , groff (GNU runoff)"