Germany won World War I, or the Imperial War as it is known in this world. The war lasted from 1914-1915 just as many had hoped it would in our world. After the war Germany allowed the conquered nations to keep their own autonomous governments. In practice, however, these were mostly puppet governments with the real power residing with the Kaiser. Berlin and London are the financial and cultural hearts of the world. The many scientists, artists, musicians and architects who would have died in World War I have transformed German cities. Berlin has numerous Neo-Gothic and Romantic skyscrapers that are taller than those in New York.
All of Russia west of the Urals came under German occupation, but everything east remained nominally independent. The Czar still rules the puppet government of German occupied Russia. Free Russia, or the Republic of Siberia as some call it, briefly dabbled in communism, but a few failed crops later and the revolutionary government was replaced by a democracy.
The German Empire's runaway success took everyone by surprise, but especially the United States. Many Americans had hoped their nation would establish colonies to compete with the other Imperial powers. Germany's post-war success motivated the desire the spread a little bit of America throughout the world. Eventually, war was declared on Mexico, albeit on some very suspect reasons. The United States also invaded several nations in the Caribbean and Central America, but in those cases claimed they did so out of a desire to protect those nations from Britain and Germany.
The Austria-Hungary has successfully become more federated and is now known as the United States of Austria and Hungry. Austria-Hungry bought Italy's former colonies from Germany following the war. The colonies were supposed to be a stepping stone towards a greater overseas empire, but managing colonies turned out to be more difficult than Austria-Hungry had originally considered.
The Ottomans have also reformed themselves and have spent the last couple decades reversing their sick man status. The empire has embraced its multicultural nature thanks to the calls for reform and is far more diverse than in our world. As a result the empire protects the rights of all minorities within its borders.
China has once again become an empire under the Zhang Dynasty following a coup against the republican government by opportunistic politicians. The resorted Chinese Empire has also spent the last few decades reversing its decline and has quickly become something of a regional power.
Japan is also a rising power. Following the war Germany sold them Indochina and several islands of Indonesia. They have further expanded their empire by invading Thailand. Japan has recently been inching closer to war with the United States over disputed claims to Borneo and the Philippines. Foreign policy experts concur America could reasonably form an alliance with China, while Japan might be able to convince Germany or Britain to come to their aid. Either a cold war is forming or else this may become another flash point for a future war.
Although Britain stayed out of the Imperial War, several French resistance/terrorist groups were funded by members of the British government hoping to regain the economic benefits of an independent France. Ironically, when the Kaiser was killed at the Imperial Musical Gala it was by members of his own government eager for a war with Britain. The two nations went to war, but fortunately it didn't last any longer than the Imperial War had. There were still loses and those killed in the Anglo-Germanic War included JRR Tolkien, CS Lewis and Ernest Hemingway.
Culturally, the world is somewhat more conservative than our world. Without the horrors of the First World War the Romantic era never really ended in Europe. Jazz is very popular in America, but has only recently found an audience across the Atlantic. Jews are still viewed rather unfavorably and face discrimination, but nowhere near what they would have under the Nazis.
Speaking of which, Hitler is currently working at a coat hanger factory after having flunked out of art school. Meanwhile, Joseph Jugashvili is a priest of the Georgian Orthodox Church.