BEST DOS MEMORY MANAGER

The best memory manager is HIMEM.SYS or real name Extended Memory Manager, it supports memory over 1GB.
The second best memory manager for low memory based machines such as 32MB is EMM386.EXE or realname Enhanced Memory Manager, it supports up to 64MB of RAM.

Both of these memory managers are in Windows 3.1 and higher and various versions of MS-DOS, DR-DOS, other brands of DOS.