Here are the informations presented on the official website :
About
SjASMPlus is Z80 Assembly Language Cross Compiler. It is available for Win32, Linux and FreeBSD (mainly 5.x) systems. It is based on SjASM source code by Sjoerd Mastijn (http://xl2s.tk).
Main Features
- Full source of assembler available under BSD license, modify and extend as you wish
- Z80/R800/Z80N/i8080/LR35902 documented and undocumented opcodes support
- Macro language, defines, array of defines
- Built-in Lua scripting engine
- Conditional assembly, block repeating
- Modules (namespaces), local and temporary labels
- Source and binary file inclusion, include paths
- Multi file output, file updating, various types of exports
- Structures to work easily with structured data in memory
- Relocation data generator to support SymbOS-like relocation of executables
- Virtual device mode for common machines: ZX 128, ZX Next, Amstrad CPC, … (pseudo op DEVICE)
- ZX Spectrum specific directives and pseudo ops (SAVESNA, SAVETAP, SAVEHOB, INCHOB, INCTRD…)
- ZX Spectrum Next specific features and directives (Z80N, 8ki memory paging, SAVENEX)
- Amstrad CPC 464/6128 specific directives (SAVECPCSNA)
- Correctness is assured by Cirrus-CI with 400+ automated tests (that's also 400+ examples of usage!)
- Fake instructions as LD HL,DE (LD H,D:LD L,E) and more
- Code inlining through colon (LD A,C:INC A:PUSH AF:IFDEF FX:LD A,D:ENDIF…)
- Very fast compilation: 1 million lines by 2-3 seconds on modern computer
- Multiline block comments and user’s messages