Multiline Ultimate Assembler is a multiline (and ultimate) assembler (and disassembler) plugin for OllyDbg. It's a perfect tool for modifying and extending a compiled executable functionality, writing code caves, etc.
The plugin works with OllyDbg v1.10, OllyDbg v2, Immunity Debugger, and x64dbg.
To install the plugin, copy the appropriate DLL file to the plugin directory:
multiasm_odbg.dll - OllyDbg v1.10.
multiasm_odbg2.dll - OllyDbg v2.
multiasm_immdbg.dll - Immunity Debugger.
multiasm_x64dbg.dp[32|64] - x64dbg.