Which viewers have the language of troff (typesetter runoff) , groff (gnu runoff)?
CREATE TABLE table_1574968_1 (
    viewer VARCHAR,
    language VARCHAR
)
SELECT viewer FROM table_1574968_1 WHERE language = "troff (typesetter runoff) , groff (GNU runoff)"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Which viewers have the language of troff (typesetter runoff) , groff (gnu runoff)? ### Input: CREATE TABLE table_1574968_1 (
    viewer VARCHAR,
    language VARCHAR
) ### Response: SELECT viewer FROM table_1574968_1 WHERE language = "troff (typesetter runoff) , groff (GNU runoff)"