diff --git a/marp/.envrc b/marp/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/marp/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/marp/.gitignore b/marp/.gitignore
new file mode 100644
index 0000000..4b7e495
--- /dev/null
+++ b/marp/.gitignore
@@ -0,0 +1,2 @@
+/*.html
+/.direnv/
diff --git a/marp/flake.lock b/marp/flake.lock
new file mode 100644
index 0000000..20f5866
--- /dev/null
+++ b/marp/flake.lock
@@ -0,0 +1,82 @@
+{
+  "nodes": {
+    "devshell": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1741473158,
+        "narHash": "sha256-kWNaq6wQUbUMlPgw8Y+9/9wP0F8SHkjy24/mN3UAppg=",
+        "owner": "numtide",
+        "repo": "devshell",
+        "rev": "7c9e793ebe66bcba8292989a68c0419b737a22a0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "devshell",
+        "type": "github"
+      }
+    },
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1754091436,
+        "narHash": "sha256-XKqDMN1/Qj1DKivQvscI4vmHfDfvYR2pfuFOJiCeewM=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "67df8c627c2c39c41dbec76a1f201929929ab0bd",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1754214453,
+        "narHash": "sha256-Q/I2xJn/j1wpkGhWkQnm20nShYnG7TI99foDBpXm1SY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "5b09dc45f24cf32316283e62aec81ffee3c3e376",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "lastModified": 1753579242,
+        "narHash": "sha256-zvaMGVn14/Zz8hnp4VWT9xVnhc8vuL3TStRqwk22biA=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "0f36c44e01a6129be94e3ade315a5883f0228a6e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "devshell": "devshell",
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/marp/flake.nix b/marp/flake.nix
new file mode 100644
index 0000000..18d9038
--- /dev/null
+++ b/marp/flake.nix
@@ -0,0 +1,24 @@
+{
+  inputs = {
+    devshell.inputs.nixpkgs.follows = "nixpkgs";
+    devshell.url = "github:numtide/devshell";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    inputs:
+    inputs.flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [ "x86_64-linux" ];
+
+      imports = [ inputs.devshell.flakeModule ];
+
+      perSystem =
+        { pkgs, ... }:
+        {
+          devshells.default = {
+            packages = [ pkgs.marp-cli ];
+          };
+        };
+    };
+}
diff --git a/marp/run b/marp/run
new file mode 100755
index 0000000..02d31cf
--- /dev/null
+++ b/marp/run
@@ -0,0 +1,3 @@
+#!/usr/bin/env sh
+
+marp slides.md --preview --watch
diff --git a/marp/slides.md b/marp/slides.md
new file mode 100644
index 0000000..593aeff
--- /dev/null
+++ b/marp/slides.md
@@ -0,0 +1,126 @@
+---
+paginate: true
+---
+
+<style>
+h1 {
+  color: #24608a;
+}
+
+a {
+  color: #24608a;
+}
+</style>
+
+# Nix for PHP Developers
+
+<br />
+
+### Oliver Davies
+
+https://www.oliverdavies.uk
+
+---
+
+What is Nix? Nixpkgs? NixOS?
+
+---
+
+Home Manager
+
+---
+
+Nixvim
+
+---
+
+Moved from Ansible
+
+---
+
+How do people have PHP installed currently?
+
+---
+
+# Who has project-specific versions of PHP?
+
+---
+
+# search.nixos.org
+
+<style scoped>
+img[alt~="center"] {
+  display: block;
+  margin: 0 auto;
+  width: 80%;
+}
+</style>
+
+![center](nix-search.png)
+
+---
+
+shell.nix
+
+---
+
+Flakes
+
+---
+
+devshells
+
+---
+
+```
+nix run nixpkgs#php -- -v
+
+PHP 8.4.10 (cli) (built: Jul  2 2025 02:22:42) (NTS)
+Copyright (c) The PHP Group
+Zend Engine v4.4.10, Copyright (c) Zend Technologies
+    with Zend OPcache v8.4.10, Copyright (c), by Zend Technologies
+```
+
+```
+nix run nixpkgs#php83 -- -v
+
+PHP 8.3.23 (cli) (built: Jul  1 2025 16:52:12) (NTS)
+Copyright (c) The PHP Group
+Zend Engine v4.3.23, Copyright (c) Zend Technologies
+    with Zend OPcache v8.3.23, Copyright (c), by Zend Technologies
+```
+
+---
+
+```
+nix develop github:opdavies/dev-shells#php82 -c composer -V
+
+PHP 8.2.28 (cli) (built: Mar 11 2025 17:58:12) (NTS)
+Copyright (c) The PHP Group
+Zend Engine v4.2.28, Copyright (c) Zend Technologies
+    with Zend OPcache v8.2.28, Copyright (c), by Zend Technologies
+Composer version 2.8.5 2025-01-21 15:23:40
+```
+
+```
+nix develop github:opdavies/dev-shells#php83 -c composer -V
+
+PHP 8.3.22 (cli) (built: Jun  3 2025 17:17:57) (NTS)
+Copyright (c) The PHP Group
+Zend Engine v4.3.22, Copyright (c) Zend Technologies
+    with Zend OPcache v8.3.22, Copyright (c), by Zend Technologies
+Composer version 2.8.5 2025-01-21 15:23:40
+```
+
+---
+
+Services.flake
+
+---
+
+# Thanks
+
+- https://www.oliverdavies.uk/nix-php-developers
+- https://www.oliverdavies.uk/presentations
+- https://www.oliverdavies.uk/daily
+- https://www.oliverdavies.uk/podcast