GodMode9 Explorer by d0k3 is a full access file browser for the Nintendo 3DS console. It gives you access to your SD card, to the FAT partitions inside your SysNAND and EmuNAND and to basically anything else. Among other functionality you can copy, delete, rename files and create folders. You can find the source here.

Changes:

[fixed] Building proper CIAs from 3DS files
[scripting] New HelloBranching.gm9 sample script by Kazuma77
[scripting] New strrep, fdummy and fill commands
[scripting] New not command (best used as in if not …, elif not …)
[scripting] filesel command now also allows browsing dirs