Get all the countries!

http://restcountries.eu/rest/v1

Currency

http://restcountries.eu/rest/v1/currency/eur

Capital City

http://restcountries.eu/rest/v1/capital/tallinn

Calling Code

http://restcountries.eu/rest/v1/callingcode/7

Region

http://restcountries.eu/rest/v1/region/africa

Sub Region

http://restcountries.eu/rest/v1/subregion/western asia

ISO 639-1 Language

http://restcountries.eu/rest/v1/lang/et

http://restcountries.eu/rest/v1/lang/no

Country Name

http://restcountries.eu/rest/v1/name/norge

http://restcountries.eu/rest/v1/name/norway

Country Code

http://restcountries.eu/rest/v1/alpha/co

http://restcountries.eu/rest/v1/alpha/col

Country Codes

http://restcountries.eu/rest/v1/alpha?codes=co;rus;no

Try it yourself