The Modern Memory Manager appeared with System 7.1.2 on Macintosh computers equipped with a PowerPC microprocessor. It appears as a setting in the Memory control panel. It is supposed to optimise performance on all PowerPC-"native" applications.
The Modern Memory Manager, in its active state, can cause some non-native application programmes to load slowly. Either restarting with the shift key held down or manually switching Modern Memory Manager off should make non-native applications start up faster.