Restarting a session is then done using the "MagiC" menu bar under Windows. Installing Magic-PC on a USB flash drive is also possible, so the emulation environment can be used on computers under Windows 7 and higher. An alternative to MagiC-PC would be Hatari (emulator), especially under other free operating systems like GNU/Linux. Because the program is written in plain C, using SDL libs and in part UAE (emulator) for multimedia and hardware, it requires quite performant processors (over 1 GHz for Atari ST/STE emulation, over 2 GHz for Atari Falcon emulation). For faster program execution the machine should be at least of the Pentium 4 or Athlon XP class respectively. The successor to MagiC-Mac X on the Apple platform is "AtariX", also coded by Andreas Kromke. It has also been released under GPL v3 lately. The software integrates in part the "Musashi 68k" emulator written in plain C. AtariX is not as optimised as its predecessor once was, but the code written in C makes it more portable. Thus it will not reach the emulation speeds the former software had, but AtariX is aimed to run under more modern macOS (up to version 10.13 "High Sierra" at least), and Intel-only Mac systems with more performant processors. Another third party system enhancement for the Atari platform was "NVDI" originally developed by Sven und Wilfried Behne. It implemented advanced and accelerated graphics functions, improved driver functionality, and productivity utilities with Atari programs. The last stand-alone version 5.02/5.03 of NVDI, released in the early 2000s, worked with standard Atari TOS, MagiC for Atari, MagiC-PC, MagiC-Mac, and extra graphics cards for Ataris (ET 4000, Matrix MatGraph, Computerinsel NOVA). As bundle with MagiC it was renamed to MVDI. NVDI offered highly optimised graphics routines in Atari environment (TOS or MagiC), emulation speed is raised under Windows and Mac OS via Magic-PC and Magic-Mac by mapping most of the Atari VDI calls to those of the host operating system. In Windows this is done using GDI calls, using native PC code for these functions. Similar functionality and higher speed for graphics was provided with MagiC-Mac, using QuickDraw calls in the classic Mac OS environment. NVDI allows for the use of up to millions of colours, for text on screen it supports Bitstream Speedo Fonts, TrueType and PostScript fonts installed on Windows and classic Mac OS, and features modernised printing capabilities via GDOS for programs, run natively on the Atari and in emulation on PC and Mac.