ECLiPSe has an efficient incremental compiler which compiles Prolog source into the instructions of an abstract machine and they are then executed by an emulator. The compiler is very fast, it compiles about 1000 lines/sec. on a Sun-4, and this makes the usual debugging cycle acceptably short. Unlike other Prolog systems, the ECLiPSe compiler generates code that can be used for debugging, so that no separate interpreter is necessary, and also the debugged code runs faster.
The ECLiPSe compiler is interactive and incremental, which means that Prolog programs are compiled during a ECLiPSe session directly into the Prolog database.
In addition, object code of ECLiPSe programs can be generated and stored into a file, which can then be loaded into a different session of ECLiPSe. See section 6.10 for more details.