# SLIME

19 Hacker News commenters recommended SLIME and 2 criticized it, November 2025 to November 2026. It was recommended in 11 of 13 months. It meets the Hacker Approved badge rule.

**Verdict:** Common Lisp development environment for Emacs, valued for its REPL, debugger and macro expansion that make Lisp feel frictionless. Critics say it is tied to Emacs and lacks polish.

## Why people recommend it

- Preferred environment for Common Lisp (5 comments): "I prefer writing Lisp with Emacs+SLIME over anything else." ([source](https://news.ycombinator.com/item?id=46996429)) "I love Common Lisp and SLIME" ([source](https://news.ycombinator.com/item?id=47958997)) "Paredit and SLIME are addictive." ([source](https://news.ycombinator.com/item?id=47154979))
- Reduces friction in Lisp development (4 comments): "Using something like SLIME also takes a lot of the pains that people have with Lisp away" ([source](https://news.ycombinator.com/item?id=47907527)) "the Emacs/Slime/CL development environment as being a more frictionless approach" ([source](https://news.ycombinator.com/item?id=49455939)) "many non-obvious design choices in the Common Lisp type system and CLOS make SLIME "just work" in almost every case." ([source](https://news.ycombinator.com/item?id=46463486))
- Debugging and macrostep expansion (3 comments): "SLIME and SLY have macrostep functionality that lets you expand macros in place, which has helped me immensely" ([source](https://news.ycombinator.com/item?id=49449704)) "With SLIME (this is a standard and very very slimmed out development aid) you add a debugger hook" ([source](https://news.ycombinator.com/item?id=49974438)) "once you get used to the debugging it's a very nice experience with slime" ([source](https://news.ycombinator.com/item?id=49280379))
- Better REPL than alternative tools (3 comments): "I have heard as a REPL experience it doesn't compare to CL with SLIME" ([source](https://news.ycombinator.com/item?id=46258287)) "LSP is actually much less capable than something like SLIME" ([source](https://news.ycombinator.com/item?id=45957280)) "the Emacs/Slime/CL development environment as being a more frictionless approach" ([source](https://news.ycombinator.com/item?id=49455939))

## What people warn about

- Tied to Emacs, lacks polish (2 comments): "It needs to escape Emacs and SLIME to something that feels complete and polished." ([source](https://news.ycombinator.com/item?id=46991724)) "we are not doomed to stay with Emacs&SLIME" ([source](https://news.ycombinator.com/item?id=47017669))

## Alternatives hackers recommend

- [Evil mode for Emacs](https://hackerapproved.com/p/evil-mode.md): 39 recommend
- [TRAMP for Emacs](https://hackerapproved.com/p/tramp.md): 25 recommend
- [Vertico](https://hackerapproved.com/p/vertico.md): 18 recommend
- [Eglot](https://hackerapproved.com/p/eglot.md): 16 recommend
- [Consult (Emacs package)](https://hackerapproved.com/p/consult.md): 16 recommend

## Cite as

Hacker Approved, "SLIME", https://hackerapproved.com/p/slime/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).