With the Duke Config utility you can set the screen resolution that Duke Nukem 3D will use and you can enable or disable having the "MouseLook" key act as a toggle. Changes to either setting are applied immediately to the duke.cfg file.
The Group Extract utility allows you to extract any or all of the files from a .grp file. First open a .grp file (or drag one to the window), then select the files you would like to extract, and finally click the Extract Selected... button to save the files. The files are saved in a folder named "<groupfilename> extracted".
The Group Build utility allows you to create new .grp files. First add the files you would like to put in a group file by clicking the Add Files... button (or just drag the files into the window), then click the Save As... button to save the new group file.
The File Updater utility currently updates user.con and defs.con files from v1.3 to v1.4 (other updates or conversions may be added in the future). These updates are done automatically as maps are added to DNML but the functioanlity is made available if you have a need for it.
To use the updater just select the file you wish to update by clicking the Set... button or by dragging the file into the window and then click the Convert button. You will be asked where you want to save the new file and the file will be saved.