OLEDB, OleDbConnection (.NET) 
 Standard security:
"Provider=msdaora;Data Source=MyOracleDB;User Id=UserName;Password=asdasd;" 
This one's from Microsoft, the following are from Oracle
 Standard Security:
"Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=Username;Password=asdasd;" 
 Trusted Connection:
"Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;OSAuthent=1;"