Note: Permission is granted to copy and use in the same way as you are allowed to copy and use the rest of PostgreSQL.
Embedded SQL has some small advantages over other ways to handle SQL queries. It takes care of all the tedious moving of information to and from variables in your C program. Many RDBMS packages support this embedded language.
There is an ANSI-standard describing how the embedded language should work. ecpg was designed to meet this standard as much as possible. So it is possible to port programs with embedded SQL written for other RDBMS packages to Postgres and thus promoting the spirit of free software.