http://billposer.org/Software/libuninum.html
Libuninum is a library that provides conversion in both directions between textual representations of numbers and integers. The library is written in C but provides a Tcl interface. Virtually all known number systems, living and dead, are covered:
Aegean
Arabic_Alphabetic
Arabic_Persian
Arabic_Western
Armenian
Balinese
Bengali
Burmese
Chinese_Counting_Rod_Early
Chinese_Counting_Rod_Late
Chinese_Counting_Rod_Early_No_Zero
Chinese_Counting_Rod_Late_No_Zero
Chinese_Legal_Simplified
Chinese_Legal_Traditional
Chinese_Regular_Simplified
Chinese_Regular_Traditional
Chinese_Regular_Place
Common_Braille
Cyrillic
Devanagari
Egyptian
Ethiopic
Ewellic_Decimal
Ewellic_Hexadecimal
French_Braille
Glagolitic
Greek_Lower
Greek_Upper
Gujarati
Gurmukhi
Hebrew_Early
Hebrew_Late
Hexadecimal_Lower
Hexadecimal_Upper
Japanese_Regular_Simplified
Japanese_Regular_Traditional
Japanese_Legal_Simplified
Japanese_Legal_Traditional
Japanese_Western_Mixed
Kannada
Kayah_Li
Kharoshthi
Khmer
Klingon
Lao
Lepcha
Limbu
Malayalam
Mandarin_Legal_Simplified
Mandarin_Legal_Traditional
Mandarin_Regular_Simplified
Mandarin_Regular_Traditional
Mongolian
Mxedruli
New_Tai_Lue
Nko
Ol_Chiki
Old_Italic
Old_Persian
Oriya
Osmanya
Phoenician
Roman_Lower
Roman_Upper
Russian_Braille
Saurashtra
Shan
Sinhala
Sundanese
Suzhou
Tamil_Place
Tamil_Traditional
Telugu
Tengwar_Decimal
Tengwar_Duodecimal
Thai
Tibetan
Vai
Verdurian
Western_Lower
Western_Upper
Xucuri_Lower
Xucuri_Upper
