Barnes, John. The Century Next Door
Divergence: 1991 CE
What if: The counter-democracy Russian coup of 1991 succeeded due to Boris Yeltsin's death, and the 1990s got progressively worse, including the mysterious death of George H.W. Bush in 1993 and the onset of the MutAIDS plague, only to get even worse as the 21st century began.
Summary: Series describing the 21st century on and off Earth.
Series note: Series including Orbital Resonance, Kaleidoscope Century, Candle, and The Sky So Big and Black.
Comments: With the initial volume, Orbital Resonance, published in 1991, the projected history would have been entirely "future history". But as subsequent books were published and Barnes held to the 1990s timeline as originally described, the series became explicitly the result of an alternate history.
Published: The first three volumes in the series are included in the omnibus The Century Next Door, SFBC 2000 (0739408852).

Barnes, John. Kaleidoscope Century
Divergence: 1991 CE
Summary: The life of a KGB/Organization agent from 1968 to 2109.
Series note: One of the Century Next Door novels.
Comments: Story is not dependent on being considered as alternate history, and in fact there is minimal development of the alternative timeline.
Published: Tor 1995 (0312855613BUY), 1996 (0812533461BUY); Millennium 1995 (1857982746); Phoenix 1996 (1857996496).
Published: Included in The Century Next Door, SFBC 2000 (0739408852).
Original in: English.
Translation: German by Martin Gilbert as Das kaleidoskopische Jahrhundert, Heyne 1996 (3453109082).

Barnes, John. The Sky So Big and Black
Divergence: 1991 CE
Summary: Set on Mars in the year 2095.
Series note: One of the Century Next Door novels.
Published: Tor 2002 (0765303035BUY), 2003 (0765342227BUY).