diff --git a/j/README.md b/j/README.md
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+# J
+
+## References
+
+- [Learning J](https://www.jsoftware.com/help/learning/contents.htm)
+- [Minimal J for Beginners](https://code.jsoftware.com/wiki/User:Devon_McCormick/MinimalBeginningJ)
+
+## Notes
+
+- `jconsole` is the REPL
+- `jqt` is for actual use
+- The nix package only includes `jconsole`
+
diff --git a/j/shell.nix b/j/shell.nix
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+with import <nixpkgs> {};
+mkShell {
+  buildInputs = [ j ];
+}