diff --git a/demo/DemoApp.tsx b/demo/DemoApp.tsx
index 0e06b57..e90abc4 100644
--- a/demo/DemoApp.tsx
+++ b/demo/DemoApp.tsx
@@ -2,7 +2,7 @@ import React, {useState} from "react";
 import "../index";
 import {Checkbox} from "../src/Components/Forms/Checkbox";
 import { Radio } from "../src/Components/Forms/Radio";
-import {FloppyDisk, TrashSimple, XCircle} from "@phosphor-icons/react";
+import {AirTrafficControl, Basket, FloppyDisk, House, TrashSimple, XCircle} from "@phosphor-icons/react";
 import {Card} from "../src/Components/Card";
 import {PasswordInput} from "../src/Components/Forms/PasswordInput";
 import {RequiredField} from "../src/Components/Forms/RequiredField";
@@ -18,7 +18,10 @@ import {MainMenu} from "../src/Components/Menus/MainMenu";
 import {SubmenuFloat} from "../src/Components/Menus/SubmenuFloat";
 import {Submenu} from "../src/Components/Menus/Submenu";
 import {SubmenuItem, SubmenuItemSubmenu} from "../src/Components/Menus/SubmenuItem";
-import {MainMenuItem, MainMenuItemSubmenu} from "../src/Components/Menus/MainMenuItem";
+import {MainMenuItemSubmenu, MainMenuLink} from "../src/Components/Menus/MainMenuItem";
+import {AppItem, AppLink, AppsMenu} from "../src/Components/Menus/AppsMenu";
+import {Application} from "../src/Application/Application";
+import {Outlet} from "react-router-dom";
 
 export function DemoApp()
 {
@@ -27,10 +30,10 @@ export function DemoApp()
 	const [selected, setSelected] = useState(null);
 
 	return (
-		<main className={"app"}>
+		<Application>
 			<MainMenu>
-				<MainMenuItem href={"/"}>Home</MainMenuItem>
-				<MainMenuItem href={"#"}>Test</MainMenuItem>
+				<MainMenuLink to={"/"}><House /> Home</MainMenuLink>
+				<MainMenuLink to={"/test"}><AirTrafficControl /> Test</MainMenuLink>
 				<MainMenuItemSubmenu submenu={
 					<Submenu>
 						<SubmenuItem>Test 1</SubmenuItem>
@@ -44,12 +47,12 @@ export function DemoApp()
 										<SubmenuItem href={"#first-last-choice"}>First last choice</SubmenuItem>
 										<SubmenuItem>Another last choice</SubmenuItem>
 									</Submenu>
-								}>Submenu in submenu</SubmenuItemSubmenu>
+								}><Basket /> Submenu in submenu</SubmenuItemSubmenu>
 							</Submenu>
-						}>Submenu</SubmenuItemSubmenu>
+						}><Basket /> Submenu</SubmenuItemSubmenu>
 					</Submenu>
 				}>
-					Submenu
+					<Basket /> Submenu
 				</MainMenuItemSubmenu>
 			</MainMenu>
 
@@ -58,12 +61,8 @@ export function DemoApp()
 			<h2>TODO</h2>
 
 			<ul>
-				<li>Dropdown menus</li>
-				<li>Main menu</li>
-				<li>Tabs / Apps selectors</li>
 				<li>App steps</li>
 				<li>Pagination</li>
-				<li>Apps</li>
 				<li>Global states</li>
 				<li>Async</li>
 				<li>Subapps</li>
@@ -89,9 +88,9 @@ export function DemoApp()
 			<button type={"button"}>A cool button</button>
 			<a className={"button"} href={"#"}>A link button</a>
 			<button type={"button"} className={"flat"}>A flat button</button>
-			<button type={"button"} className={"validation"}><FloppyDisk weight={"bold"}/> A validation button</button>
-			<button type={"button"} className={"cancel"}><XCircle weight={"bold"}/> A cancellation button</button>
-			<button type={"button"} className={"delete"}><TrashSimple weight={"bold"}/> A deletion button</button>
+			<button type={"button"} className={"validation"}><FloppyDisk /> A validation button</button>
+			<button type={"button"} className={"cancel"}><XCircle /> A cancellation button</button>
+			<button type={"button"} className={"delete"}><TrashSimple /> A deletion button</button>
 
 			<h2>Forms</h2>
 
@@ -303,15 +302,34 @@ export function DemoApp()
 					<SubmenuItemSubmenu submenu={
 						<Submenu>
 							<SubmenuItem>Test A</SubmenuItem>
-							<SubmenuItem>Test B</SubmenuItem>
+							<SubmenuItem><AirTrafficControl /> Test B</SubmenuItem>
 						</Submenu>
 					}>
-						Submenu
+						<Basket /> Submenu
 					</SubmenuItemSubmenu>
 				</Submenu>
 			} floatingOptions={{ placement: "right-start" }}>
 				<button>Submenu on a button</button>
 			</SubmenuFloat>
-		</main>
+
+			<h2>App selectors</h2>
+
+			<AppsMenu>
+				<AppLink to={"/"}>
+					<House />
+					Home
+				</AppLink>
+				<AppLink to={"/test"}>
+					<AirTrafficControl />
+					Test link
+				</AppLink>
+				<AppItem>
+					<Basket />
+					Test 3
+				</AppItem>
+			</AppsMenu>
+
+			<Outlet />
+		</Application>
 	);
 }
diff --git a/demo/NavTest.tsx b/demo/NavTest.tsx
new file mode 100644
index 0000000..1afa84e
--- /dev/null
+++ b/demo/NavTest.tsx
@@ -0,0 +1,14 @@
+import React from "react";
+import {Card} from "../src/Components/Card";
+
+/**
+ * Navigation test component.
+ */
+export function NavTest()
+{
+	return (
+		<Card>
+			This is a navigation test.
+		</Card>
+	)
+}
diff --git a/demo/demo.tsx b/demo/demo.tsx
index 1d3361d..8ce8eb1 100644
--- a/demo/demo.tsx
+++ b/demo/demo.tsx
@@ -1,11 +1,32 @@
 import React from "react";
 import {createRoot} from "react-dom/client";
 import {DemoApp} from "./DemoApp";
+import {createBrowserRouter} from "react-router-dom";
+import {Kernel} from "../src/Application/Kernel";
+import {NavTest} from "./NavTest";
+
+// Router initialization.
+const router = createBrowserRouter([
+	{
+		path: "/",
+		element: <DemoApp />,
+		children: [
+			{
+				path: "test",
+				element: <NavTest />,
+			}
+		],
+	}
+])
 
 document.addEventListener("DOMContentLoaded", () => {
 	const demoApp = document.getElementById("demo-app");
 
 	const root = createRoot(demoApp);
 
-	root.render(<DemoApp />);
+	root.render(<Kernel router={router} footer={
+		<footer>
+			Footer test.
+		</footer>
+	} />);
 });
diff --git a/package.json b/package.json
index 5d82e6e..b0d221c 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,8 @@
     "@fontsource-variable/source-serif-4": "^5.0.19",
     "@phosphor-icons/react": "^2.1.5",
     "react": "^18.3.1",
-    "react-merge-refs": "^2.1.1"
+    "react-merge-refs": "^2.1.1",
+    "react-router-dom": "^6.24.1"
   },
   "devDependencies": {
     "@types/react": "^18.3.3",
diff --git a/src/Application/Application.tsx b/src/Application/Application.tsx
new file mode 100644
index 0000000..3676892
--- /dev/null
+++ b/src/Application/Application.tsx
@@ -0,0 +1,13 @@
+import React from "react";
+
+/**
+ * Main Kernel UI application.
+ */
+export function Application({children}: React.PropsWithChildren<{}>)
+{
+	return (
+		<main className={"app"}>
+			{children}
+		</main>
+	);
+}
diff --git a/src/Application/Kernel.tsx b/src/Application/Kernel.tsx
new file mode 100644
index 0000000..7aef8b0
--- /dev/null
+++ b/src/Application/Kernel.tsx
@@ -0,0 +1,24 @@
+import { IconContext } from "@phosphor-icons/react";
+import React from "react";
+import {createBrowserRouter, RouterProvider} from "react-router-dom";
+
+/**
+ * Main Kernel UI app component which initializes everything.
+ */
+export function Kernel({header, footer, router}: {
+	header?: React.ReactNode;
+	footer?: React.ReactNode;
+	router: ReturnType<typeof createBrowserRouter>;
+})
+{
+	return (
+		<IconContext.Provider value={{
+			size: 16,
+			weight: "bold",
+		}}>
+			{header}
+			<RouterProvider router={router} />
+			{footer}
+		</IconContext.Provider>
+	);
+}
diff --git a/src/Components/Dates/Datepicker.tsx b/src/Components/Dates/Datepicker.tsx
index edf6ceb..188882e 100644
--- a/src/Components/Dates/Datepicker.tsx
+++ b/src/Components/Dates/Datepicker.tsx
@@ -46,7 +46,7 @@ export function Datepicker({date, onDateSelected, locale, className, ...divProps
 						onDateSelected(newDate);
 					}, [date, onDateSelected])
 				}>
-					<CaretLeft weight={"bold"}/>
+					<CaretLeft />
 				</button>
 			</Tooltip>
 			<Tooltip content={nextMonthName}>
@@ -57,7 +57,7 @@ export function Datepicker({date, onDateSelected, locale, className, ...divProps
 						onDateSelected(newDate);
 					}, [date, onDateSelected])
 				}>
-					<CaretRight weight={"bold"}/>
+					<CaretRight />
 				</button>
 			</Tooltip>
 		</div>
diff --git a/src/Components/Forms/Checkbox.tsx b/src/Components/Forms/Checkbox.tsx
index a3fd756..3fd9fc6 100644
--- a/src/Components/Forms/Checkbox.tsx
+++ b/src/Components/Forms/Checkbox.tsx
@@ -7,7 +7,7 @@ export function Checkbox({children, className, type, ...inputProps}: React.Props
 	return (
 		<label className={classes("box", className)}>
 			<input type={"checkbox"} {...inputProps} />
-			<a className={"button"} tabIndex={-1}><Check weight={"bold"} /></a>
+			<a className={"button"} tabIndex={-1}><Check /></a>
 			{children}
 		</label>
 	);
diff --git a/src/Components/Forms/PasswordInput.tsx b/src/Components/Forms/PasswordInput.tsx
index 1cd5197..4b57ee3 100644
--- a/src/Components/Forms/PasswordInput.tsx
+++ b/src/Components/Forms/PasswordInput.tsx
@@ -15,7 +15,7 @@ export function PasswordInput({children, className, type, ...props}: React.Props
 					setShowPassword(!showPassword);
 				}}>
 					{
-						showPassword ? <EyeSlash weight={"bold"} /> : <Eye weight={"bold"} />
+						showPassword ? <EyeSlash /> : <Eye />
 					}
 				</a>
 			</div>
diff --git a/src/Components/Forms/Radio.tsx b/src/Components/Forms/Radio.tsx
index 9e24aa0..ea64198 100644
--- a/src/Components/Forms/Radio.tsx
+++ b/src/Components/Forms/Radio.tsx
@@ -7,7 +7,7 @@ export function Radio({children, className, type, ...inputProps}: React.PropsWit
 	return (
 		<label className={classes("box", className)}>
 			<input type={"radio"} {...inputProps} />
-			<a className={"button"} tabIndex={-1}><Check weight={"bold"} /></a>
+			<a className={"button"} tabIndex={-1}><Check /></a>
 			{children}
 		</label>
 	);
diff --git a/src/Components/Menus/AppsMenu.tsx b/src/Components/Menus/AppsMenu.tsx
new file mode 100644
index 0000000..e4a1db2
--- /dev/null
+++ b/src/Components/Menus/AppsMenu.tsx
@@ -0,0 +1,54 @@
+import React from "react";
+import {classes} from "../../Utils";
+import {IconContext} from "@phosphor-icons/react";
+import {NavLink, NavLinkProps} from "react-router-dom";
+
+/**
+ * Main apps menu component.
+ */
+export function AppsMenu({className, children, ...props}: React.HTMLAttributes<HTMLDivElement>)
+{
+	return (
+		<IconContext.Consumer>
+			{(value) => (
+				<IconContext.Provider value={Object.assign({}, value, {
+					size: 40,
+				})}>
+					<nav className={classes("apps", "menu", className)} {...props}>
+						<ul>
+							{children}
+						</ul>
+					</nav>
+				</IconContext.Provider>
+			)}
+		</IconContext.Consumer>
+	);
+}
+
+/**
+ * Component of an app item in apps menu.
+ */
+export function AppItem({className, children, ...props}: React.HTMLAttributes<HTMLAnchorElement>)
+{
+	return (
+		<li>
+			<a className={classes("app", "flat button", className)} {...props}>
+				{children}
+			</a>
+		</li>
+	);
+}
+
+/**
+ * Component of an app link in apps menu.
+ */
+export function AppLink({className, children, ...props}: NavLinkProps & React.HTMLAttributes<HTMLAnchorElement>)
+{
+	return (
+		<li>
+			<NavLink className={classes("app", "flat button", className)} {...props}>
+				{children}
+			</NavLink>
+		</li>
+	);
+}
diff --git a/src/Components/Menus/MainMenuItem.tsx b/src/Components/Menus/MainMenuItem.tsx
index ef4c202..278b569 100644
--- a/src/Components/Menus/MainMenuItem.tsx
+++ b/src/Components/Menus/MainMenuItem.tsx
@@ -1,7 +1,11 @@
 import React from "react";
 import {classes, Modify} from "../../Utils";
 import {SubmenuFloat} from "./SubmenuFloat";
+import {NavLink, NavLinkProps} from "react-router-dom";
 
+/**
+ * Main menu item properties.
+ */
 export type MainMenuItemProperties = React.PropsWithChildren<Modify<React.AnchorHTMLAttributes<HTMLAnchorElement>, {
 }>>;
 
@@ -17,6 +21,24 @@ export const MainMenuItem = React.forwardRef<HTMLAnchorElement, MainMenuItemProp
 	);
 });
 
+/**
+ * A main menu item link properties.
+ */
+export type MainMenuLinkProperties = React.PropsWithChildren<Modify<NavLinkProps & React.AnchorHTMLAttributes<HTMLAnchorElement>, {
+}>>;
+
+/**
+ * A main menu item link.
+ */
+export const MainMenuLink = React.forwardRef<HTMLAnchorElement, MainMenuLinkProperties>(function MainMenuLink({children, ...props}: MainMenuLinkProperties, ref)
+{
+	return (
+		<li>
+			<NavLink ref={ref} {...props}>{children}</NavLink>
+		</li>
+	);
+});
+
 /**
  * A main menu item that open a submenu.
  */
diff --git a/src/Components/Menus/SubmenuItem.tsx b/src/Components/Menus/SubmenuItem.tsx
index 1a5dccb..0b750fa 100644
--- a/src/Components/Menus/SubmenuItem.tsx
+++ b/src/Components/Menus/SubmenuItem.tsx
@@ -1,7 +1,11 @@
 import React from "react";
 import {classes, Modify} from "../../Utils";
 import {SubmenuFloat} from "./SubmenuFloat";
+import {NavLink, NavLinkProps} from "react-router-dom";
 
+/**
+ * Submenu item properties.
+ */
 export type SubmenuItemProperties = React.PropsWithChildren<Modify<React.AnchorHTMLAttributes<HTMLAnchorElement>, {
 }>>;
 
@@ -15,6 +19,22 @@ export const SubmenuItem = React.forwardRef<HTMLAnchorElement, SubmenuItemProper
 	);
 });
 
+/**
+ * A submenu item link properties.
+ */
+export type SubmenuLinkProperties = React.PropsWithChildren<Modify<NavLinkProps & React.AnchorHTMLAttributes<HTMLAnchorElement>, {
+}>>;
+
+/**
+ * A submenu item link.
+ */
+export const SubmenuLink = React.forwardRef<HTMLAnchorElement, SubmenuLinkProperties>(function SubmenuLink({className, children, ...props}: SubmenuLinkProperties, ref)
+{
+	return (
+		<NavLink ref={ref} className={classes("item", className)} {...props}>{children}</NavLink>
+	);
+});
+
 /**
  * A submenu item that open a submenu.
  */
diff --git a/src/Components/Select/OptionsSuggestions.tsx b/src/Components/Select/OptionsSuggestions.tsx
index dbaea7b..6e6a06d 100644
--- a/src/Components/Select/OptionsSuggestions.tsx
+++ b/src/Components/Select/OptionsSuggestions.tsx
@@ -126,7 +126,7 @@ export function OptionsSuggestions<OptionKey extends keyof any, Option>({options
 		   onClick={() => { onSelected(key, option); }}>
 			{(renderOption ?? defaultRenderOption)(option)}
 
-			<span className={"selected"}><Check weight={"bold"} /></span>
+			<span className={"selected"}><Check /></span>
 		</a>
 	));
 }
diff --git a/src/Components/Select/Select.tsx b/src/Components/Select/Select.tsx
index e3852a2..1261cfc 100644
--- a/src/Components/Select/Select.tsx
+++ b/src/Components/Select/Select.tsx
@@ -205,17 +205,17 @@ export function Select<OptionKey extends keyof any, Option>(
 					       {...props} />
 				</Suggestible>
 
-				<a className={"button"} tabIndex={-1}><CaretDown weight={"bold"}/></a>
+				<a className={"button"} tabIndex={-1}><CaretDown /></a>
 			</div>
 
 			<ul className={"selected"}>
 				{ // Showing each selected value.
 					selectedOptions.map(([optionKey, option]) => (
 						<li key={String(optionKey)}>
-							<Check weight={"bold"}/>
+							<Check />
 							<div className={"option"}>{(renderOption ?? defaultRenderOption)(option)}</div>
 							<button className={"remove flat"} type={"button"} onClick={() => handleDeselectedOption(optionKey)}>
-								<X weight={"bold"}/>
+								<X />
 							</button>
 						</li>
 					))
diff --git a/src/styles/_colors.less b/src/styles/_colors.less
index c4653e5..b93d2e4 100644
--- a/src/styles/_colors.less
+++ b/src/styles/_colors.less
@@ -85,4 +85,5 @@
 
 
 	@menu-hover: rgba(255, 255, 255, 0.15); --menu-hover: @menu-hover;
+	@menu-active: rgba(0, 0, 0, 0.125); --menu-active: @menu-active;
 }
diff --git a/src/styles/components/_button.less b/src/styles/components/_button.less
index d6178bd..335d8dd 100644
--- a/src/styles/components/_button.less
+++ b/src/styles/components/_button.less
@@ -152,13 +152,13 @@ a.button, button, input[type="submit"], input[type="reset"]
 	}
 
 	svg
-	{ // Icon style.*
+	{ // Icon style.
 		display: inline-block;
 		margin-top: -0.2em;
 		margin-right: 0.2em;
 		vertical-align: middle;
 	}
-	> svg:last-of-type
+	&.icon-only svg
 	{
 		margin-right: 0.05em;
 	}
diff --git a/src/styles/components/_menus.less b/src/styles/components/_menus.less
index 3bc0861..a1c45f2 100644
--- a/src/styles/components/_menus.less
+++ b/src/styles/components/_menus.less
@@ -1,2 +1,3 @@
+@import "menus/_apps-menu";
 @import "menus/_main-menu";
 @import "menus/_submenu";
diff --git a/src/styles/components/menus/_apps-menu.less b/src/styles/components/menus/_apps-menu.less
new file mode 100644
index 0000000..851f42c
--- /dev/null
+++ b/src/styles/components/menus/_apps-menu.less
@@ -0,0 +1,49 @@
+nav.apps.menu
+{
+	> ul
+	{
+		display: flex;
+		flex-direction: row;
+		align-items: flex-start;
+		justify-content: center;
+		gap: 0.66em;
+
+		margin: auto;
+		padding: 0;
+
+		list-style: none;
+
+		> li
+		{
+			padding: 0;
+		}
+	}
+
+	a.app
+	{
+		display: flex;
+		flex-direction: column;
+		align-items: center;
+		justify-content: center;
+
+		margin: auto;
+		padding: 1em;
+		min-width: 10em;
+
+		font-size: 1.1em;
+
+		svg
+		{
+			display: block;
+			margin: 0 auto 0.5em auto;
+
+			color: var(--primary);
+		}
+
+		&.active
+		{
+			outline: solid 2px var(--primary);
+			outline-offset: 2px;
+		}
+	}
+}
diff --git a/src/styles/components/menus/_main-menu.less b/src/styles/components/menus/_main-menu.less
index ffe1217..f49e922 100644
--- a/src/styles/components/menus/_main-menu.less
+++ b/src/styles/components/menus/_main-menu.less
@@ -1,8 +1,13 @@
 nav.main.menu
 {
+	position: sticky;
+	top: 0;
+
 	background: var(--primary-gradient);
 	color: var(--background);
 
+	z-index: 2;
+
 	.floating
 	{
 		justify-content: flex-start;
@@ -47,6 +52,19 @@ nav.main.menu
 				{
 					background: var(--menu-hover);
 				}
+
+				&.active
+				{
+					background: var(--menu-active);
+				}
+
+				svg
+				{ // Icon style.
+					display: inline-block;
+					margin-top: -0.2em;
+					margin-right: 0.2em;
+					vertical-align: middle;
+				}
 			}
 		}
 	}
@@ -68,6 +86,11 @@ nav.main.menu
 				{
 					background: var(--menu-hover);
 				}
+
+				&.active
+				{
+					background: var(--menu-active);
+				}
 			}
 		}
 	}
diff --git a/src/styles/components/menus/_submenu.less b/src/styles/components/menus/_submenu.less
index 166aee1..d002b13 100644
--- a/src/styles/components/menus/_submenu.less
+++ b/src/styles/components/menus/_submenu.less
@@ -12,7 +12,7 @@
 		justify-content: flex-end;
 	}
 
-	.submenu
+	> .submenu
 	{
 		display: flex;
 		flex-direction: column;
@@ -32,6 +32,14 @@
 			{
 				background: var(--background-darker);
 			}
+
+			svg
+			{ // Icon style.
+				display: inline-block;
+				margin-top: -0.2em;
+				margin-right: 0.2em;
+				vertical-align: middle;
+			}
 		}
 	}
 }
diff --git a/yarn.lock b/yarn.lock
index edf1fe6..2842f13 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -651,6 +651,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@remix-run/router@npm:1.17.1":
+  version: 1.17.1
+  resolution: "@remix-run/router@npm:1.17.1"
+  checksum: 10c0/bee1631feb03975b64e1c7b574da432a05095dda2ff0f164c737e4952841a58d7b9861de87bd13a977fd970c74dcf8c558fc2d26c6ec01a9ae9041b1b4430869
+  languageName: node
+  linkType: hard
+
 "@rollup/pluginutils@npm:^5.1.0":
   version: 5.1.0
   resolution: "@rollup/pluginutils@npm:5.1.0"
@@ -1826,6 +1833,7 @@ __metadata:
     react: "npm:^18.3.1"
     react-dom: "npm:^18.3.1"
     react-merge-refs: "npm:^2.1.1"
+    react-router-dom: "npm:^6.24.1"
     typescript: "npm:^5.4.5"
     vite: "npm:^5.2.11"
     vite-plugin-dts: "npm:^3.9.1"
@@ -2313,6 +2321,30 @@ __metadata:
   languageName: node
   linkType: hard
 
+"react-router-dom@npm:^6.24.1":
+  version: 6.24.1
+  resolution: "react-router-dom@npm:6.24.1"
+  dependencies:
+    "@remix-run/router": "npm:1.17.1"
+    react-router: "npm:6.24.1"
+  peerDependencies:
+    react: ">=16.8"
+    react-dom: ">=16.8"
+  checksum: 10c0/458c6c539304984c47b0ad8d5d5b1f8859cc0845e47591d530cb4fcb13498f70a89b42bc4daeea55d57cfa08408b453bcf601cabb2c987f554cdcac13805caa8
+  languageName: node
+  linkType: hard
+
+"react-router@npm:6.24.1":
+  version: 6.24.1
+  resolution: "react-router@npm:6.24.1"
+  dependencies:
+    "@remix-run/router": "npm:1.17.1"
+  peerDependencies:
+    react: ">=16.8"
+  checksum: 10c0/f50c78ca52c5154ab933c17708125e8bf71ccf2072993a80302526a0a23db9ceac6e36d5c891d62ccd16f13e60cd1b6533a2036523d1b09e0148ac49e34b2e83
+  languageName: node
+  linkType: hard
+
 "react@npm:^18.3.1":
   version: 18.3.1
   resolution: "react@npm:18.3.1"