SASM
Simple crossplatform IDE for NASM, MASM, GAS and FASM languages
...In SASM you can easily develop and execute programs, written in NASM, MASM, GAS or FASM assembly languages. Enter code in form and simply run your program. In Windows SASM can execute programs in a separate window. Enter your input data in "Input" docking field. In "Output" field you can see the result of the execution of the program. Wherein all messages and compilation errors will be shown in the form on the bottom. You can save source or already compiled (exe) code of your program to file and load your programs from file.