In this althistory Latin alphabet is called Roman alphabet and it is used as IAS (International Auxillary Script).
Writing systems derived from Latin alphabet in this althistory are:
Angular Alphabet, used in Americas,
Crosshatch Alphabet, used in Scandinavia, England and OTL Northern Germany,
Western European Alphabet, used in West Europe,
Croatian Alphabet (first used in Croatia), used in Slavophone (Slavic languages-speaking) and Celtophone (Celtic languages-speaking) countries
Et cetera ...