16 June 2026
Christoph Neumann
Welcome to the Clojure Deref! This is a weekly link/news roundup for the Clojure ecosystem (feed: RSS).
Would you like to learn more about optimizing Clojure code? Anders Murphy investigated the performance of UUIDs as primary keys in SQLite. Also, Sashko Yakushev spent some time improving the performance of clojure-lsp. Learn from their experience, and if you’ve never had a chance, read about clj-async-profiler and differential flamegraphs. Useful tools!
And speaking of performance, FlowStorm 4.6.0 was
released. It added support for async and await in ClojureScript. Calling
FlowStorm a "debugger" only scratches the surface of what it can do. Take a
look at its ClojureScript support.
On the subject of Clojure dialects, Jolt, a new dialect hosted on Janet, has been making rapid progress since last week. It supports nREPL, Ring, deps.edn, Selmer, HoneySQL, and more. Join the #jolt channel on Clojurians Slack to keep up on all the latest developments. Jolt joins let-go, Glojure and Phel as Clojure dialects seeing a surge in development due to LLMs.
If you use Emacs, check out CIDER 1.22.0 which is out after 4 months of development work. Thanks to funding from Clojurists Together and others, Bozhidar was able to tackle some problems that have been bugging him for years! Perhaps they were also bugging you?
When you’re not editing Clojure application code, perhaps you’d like to edit some 3D shapes as Clojure code. For that, look no further than Ridley: a turtle graphics 3D modeling tool. Try it out online.
Clojure core can map, filter, and reduce millions of maps in memory, but should you? If your data situation has gotten to that point, you might want Flatiron, an in-memory columnar analytics library. Load your data and try some grouping, aggregating, filtering, and sorting—all in process, without a database.
Do you love immutable history but hate running out of storage? Use Event Store to save all your events in a minimal, append-only log in any S3-compatible object-store.
Business workflows and form logic may not be the most captivating technology in software engineering these days, but if you need to make a bunch of form-data screens, Stepvine is a new project to help. It is a "server-authoritative reactive form & app builder." You describe your forms as EDN data, and it runs all the logic on the server while keeping the UI responsive using Datastar.
You know what we say in the Clojure community: "the library isn’t dead, it’s just done." Well, sometimes it takes 7 years to discover it’s not done, and so, it was time to release again again, this time with circuit breakers. And if one day again, it’s time to release again, we look forward to seeing again again.
Save the date! HeartConf 2027 is happening August 18-19, 2027, in Mechelen, Belgium. It is the successor to Heart of Clojure, still with a strong Clojure representation, but also inviting friends from other communities.
Clojure/Conj 2026: Sep 30-Oct 2. Charlotte, NC, USA. Early Bird tickets.
EuroClojure 2027: May 19-21, 2027. Prague, Czech Republic. Join the mailing list
Deploying Ring Vs. Deploying Rails - A Rant. - Clojure Diary
Finding transitive var usages with clj-kondo - Michiel Borkent
Glint: Dev diary IV - One step forward, two steps back - Emil Bengtsson
Parediting in Helix - Tom Waddington
Navball MFD in sfsim - Jan Wedekind
Clojure is almost as fast as C (with some help) - Ertuğrul Çetin
Announcing ClojureSSH - Crispin Wellington
Deploying Ring App on Ubuntu 26.04 - Karthikeyan A K
biff.fx: lightweight effects system - Jacob O’Bryant
CIDER 1.22 (“São Miguel”) - Bozhidar Batsov
Making budget models punch above their weight with a smart harness - Dmitri Sotnikov
Debut release
flatiron - A columnar database for analytics
weowe - A native Android app (ClojureDart/Flutter) for tracking shared expenses between people. Local-first.
dvergr - FRP-based LLM agent framework with git-like memory model.
clj-colors - A color palette utility intended for generative art with clojure.
clojuressh - A Clojure library for using SSH in Clojure that is API compatible with bbssh
libl.in - A URL redirect app for all Codeberg users
eventstore - A minimal, production-oriented append-only event log, backed by S3-compatible object storage.
todo-sqlite-eventstore - A basic todo app that stores events in Tigris Data and uses SQLite for the projected todos read model. Events are the source of truth; the todos table is rebuilt from projections.
biff.fx - Turn your functions into pure state machines.
biff.config - A light Biff wrapper around Aero.
stepvine - form building platform
Updates
sci 0.13.52 - Configurable Clojure/Script interpreter suitable for scripting and Clojure DSLs
phel-lang 0.44.0 - A functional, Lisp-inspired language that compiles to PHP. Inspired by Clojure, Phel brings macros, persistent data structures, and expressive functional idioms to the PHP ecosystem.
flow-storm-debugger 4.6.0 - A debugger for Clojure and ClojureScript with some unique features.
bareforge 0.7.1 - Companion visual builder for BareDOM web components. Drag components, declare reactive state, export fully interactive CLJS or JS project
mount 0.1.24 - managing Clojure and ClojureScript app state since (reset)
quiescent 0.3.0 - A Clojure library for composable async tasks with automatic parallelization, structured concurrency, and parent-child and chain cancellation
promesa 12.0.0 - A promise library & concurrency toolkit for Clojure and ClojureScript.
teensyp 0.6.4 - A small, zero-dependency Clojure TCP server that uses Java NIO
yggdrasil 0.2.29 - Git-like, causal space-time lattice abstraction over systems supporting this memory model.
hawk 1.0.14 - It watches your code like a hawk! You like tests, right? Then run them with our state-of-the-art Clojure test runner.
spindel 0.1.23 - Cross-platform FRP runtime with a git-like memory model.
pg-datahike 0.1.45 - Postgres compatibility layer for Datahike.
ClojureScriptStorm 1.12.145-1 - A fork of the official ClojureScript compiler with extra code to make it a dev compiler
charred 1.039 - zero dependency efficient read/write of json and csv data.
ridley 3.1.0 - A turtle graphics-based 3D modeling tool for 3D printing. Write Clojure scripts, see real-time 3D preview, export STL. WebXR support for VR/AR visualization.
raster 0.1.3 - Fast, functional numerical computing for Clojure/JVM.
html 0.2.5 - Html generation library inspired by squint’s html tag
dataspex 2026.06.3 - See the shape of your data: point-and-click Clojure(Script) data browser
stratum 0.3.75 - Versioned, fast and scalable columnar database.
clj-tg-bot-api 1.2.270 - 🤖 The latest Telegram Bot API spec and client lib for Clojure-based apps
svar 0.7.29 - Type‑safe LLM output for Clojure. Works with any text‑only model.
ansatz 0.1.58 - Dependently typed Clojure DSL with a Lean4 compatible kernel.
cider 1.22.0 - The Clojure Interactive Development Environment that Rocks for Emacs
deft 0.2.0 - A collection of macros designed to address issues with objects in Clojure.
