Scilab scripts can be ideally written in any editor. Scilab has its own editor, also called as Scinotes. You can open this editor by typing editorin the Scilab console. If you want to open an already existing script file, click on the File menu and then click on Open. Then browse to the location where the file is and click on Ok.  Use the Newoption in place of the Open option to open a new blank editor window.