- Array indices start at 0. :) [Half-joking.] - An excellent debugger and condition system! - Code won’t be broken in 20 years (which I value when developing

- Array indices start at 0. :) [Half-joking.] - An excellent debugger and condition system! - Code won’t be broken in 20 years (which I value when developing things like compilers). There’s one standard, and several de facto standard extensions. - Almost 30 years of history, documentation, discussions, etc. Every corner of the language has been discussed to death. - Several stable, mature, and independent choices of open source implementation. - Implementations are written in Lisp all the way down. You can immediately jump to the definition of anything at any depth, and often edit or redefine to taste. (Example, I improved SBCL’s integer square root in my live image, and submitted a patch.) The only off-limits bits are a part of the runtime, like the garbage collector. - Several independent choices of commercial implementation and commercial support. - Generally easy to optimize and micro-optimize code. Easy to edit/disassemble/debug. - Easy to write assembly code with SBCL. - Fast start-up time, easy to compile into native executables. No JIT lags. - Excellent IDE support through Emacs and SLIME. Incremental development is real with Lisp, and absolutely not so with Julia. - Easy to dynamically generate and compile code at runtime. - Excellent metasyntactic programming facilities. (Macros, symbol macros, reader macros, ...) Negatives compared to Julia: - Poor support for numerical libraries and poor support for plotting, much to the chagrin of a scientific programmer like myself. - No hip website or hip foundation backing it. - Quiet community, with very broad interests. Not everybody is rallying around one theme in Lisp. You got database programmers, game programmers, scientific programmers, etc. This could be a positive, if the community were larger.