diff --git a/Cargo.toml b/Cargo.toml
index d1ac279a..dd175f42 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -66,7 +66,7 @@ parking_lot = "0.12.5"
 postcard = { version = "1.0.8", features = ["use-std"] }
 replace_with = "0.1.8"
 serde = { version = "1.0.164", features = ["derive"] }
-serde_json = "1.0.116"
+serde_json = "1.0.149"
 serde_tuple = "1.1.2"
 smallbox = "0.8.8"
 static_assertions = "1.1.0"
diff --git a/applications/Cargo.toml b/applications/Cargo.toml
index 91422207..bf2f917c 100644
--- a/applications/Cargo.toml
+++ b/applications/Cargo.toml
@@ -15,6 +15,7 @@ massive-input.workspace = true
 anyhow.workspace = true
 derive_more.workspace = true
 log.workspace = true
+serde_json.workspace = true
 tokio.workspace = true
 uuid.workspace = true
 # Architecture: We should get rid of the winit dependency here. Current ViewEvent depends on it, 
diff --git a/applications/src/instance_context.rs b/applications/src/instance_context.rs
index 9aa98681..8bc9aaa7 100644
--- a/applications/src/instance_context.rs
+++ b/applications/src/instance_context.rs
@@ -11,14 +11,14 @@ use massive_renderer::FontManager;
 use massive_util::{CoalescingKey, CoalescingReceiver};
 
 use crate::{
-    InstanceEnvironment, InstanceId, Scene, ViewEvent, ViewExtent, ViewId,
+    InstanceEnvironment, InstanceId, InstanceParameters, Scene, ViewEvent, ViewExtent, ViewId,
     view::{ViewCommand, ViewCreationInfo},
     view_builder::ViewBuilder,
 };
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CreationMode {
-    New,
+    New(InstanceParameters),
     Restore,
 }
 
@@ -57,8 +57,15 @@ impl InstanceContext {
         self.id
     }
 
-    pub fn creation_mode(&self) -> CreationMode {
-        self.creation_mode
+    pub fn creation_mode(&self) -> &CreationMode {
+        &self.creation_mode
+    }
+
+    pub fn parameters(&self) -> Option<&InstanceParameters> {
+        match &self.creation_mode {
+            CreationMode::New(map) => Some(map),
+            CreationMode::Restore => None,
+        }
     }
 
     pub fn primary_monitor_scale_factor(&self) -> f64 {
diff --git a/applications/src/instance_environment.rs b/applications/src/instance_environment.rs
index 055b50e7..9adce5d3 100644
--- a/applications/src/instance_environment.rs
+++ b/applications/src/instance_environment.rs
@@ -1,4 +1,5 @@
 use massive_renderer::FontManager;
+use serde_json::{Map, Value};
 use tokio::sync::mpsc::UnboundedSender;
 
 use crate::{InstanceCommand, InstanceId};
@@ -9,8 +10,11 @@ pub struct InstanceEnvironment {
     // Robustness: This might change on runtime.
     pub(crate) primary_monitor_scale_factor: f64,
     pub(crate) font_manager: FontManager,
+    pub(crate) parameters: Map<String, Value>,
 }
 
+pub type InstanceParameters = Map<String, Value>;
+
 impl InstanceEnvironment {
     pub fn new(
         requests_tx: UnboundedSender<(InstanceId, InstanceCommand)>,
@@ -21,6 +25,12 @@ impl InstanceEnvironment {
             command_sender: requests_tx,
             primary_monitor_scale_factor,
             font_manager,
+            parameters: Default::default(),
         }
     }
+
+    pub fn with_parameters(mut self, parameters: InstanceParameters) -> Self {
+        self.parameters = parameters;
+        self
+    }
 }
diff --git a/desktop/Cargo.toml b/desktop/Cargo.toml
index 714c3386..35a47c88 100644
--- a/desktop/Cargo.toml
+++ b/desktop/Cargo.toml
@@ -23,6 +23,7 @@ derive_more.workspace = true
 euclid.workspace = true
 futures.workspace = true
 log.workspace = true
+serde_json.workspace = true
 serde.workspace = true
 tokio = { workspace = true, features = ["time"] }
 toml.workspace = true
diff --git a/desktop/src/desktop.rs b/desktop/src/desktop.rs
index fc8c5ab6..bf2b95f5 100644
--- a/desktop/src/desktop.rs
+++ b/desktop/src/desktop.rs
@@ -6,8 +6,8 @@ use tokio::sync::mpsc::{UnboundedReceiver, unbounded_channel};
 use uuid::Uuid;
 
 use massive_applications::{
-    CreationMode, InstanceCommand, InstanceEnvironment, InstanceEvent, InstanceId, ViewCommand,
-    ViewEvent, ViewId, ViewRole,
+    CreationMode, InstanceCommand, InstanceEnvironment, InstanceEvent, InstanceId,
+    InstanceParameters, ViewCommand, ViewEvent, ViewId, ViewRole,
 };
 use massive_input::{EventManager, ExternalEvent};
 use massive_renderer::RenderPacing;
@@ -72,7 +72,10 @@ impl Desktop {
             .get_named(&env.primary_application)
             .expect("No primary application");
 
-        instance_manager.spawn(primary_application, CreationMode::New)?;
+        instance_manager.spawn(
+            primary_application,
+            CreationMode::New(InstanceParameters::new()),
+        )?;
 
         // First wait for the initial view that's being created.
 
@@ -201,6 +204,7 @@ impl Desktop {
             }
             UserIntent::StartInstance {
                 originating_instance,
+                parameters,
             } => {
                 // Feature: Support starting non-primary applications.
                 let application = self
@@ -211,7 +215,7 @@ impl Desktop {
 
                 let instance = self
                     .instance_manager
-                    .spawn(application, CreationMode::New)?;
+                    .spawn(application, CreationMode::New(parameters))?;
 
                 // Simplify: Use the currently focused instance for determining the originating one.
                 let band_location = self
diff --git a/desktop/src/desktop_interaction.rs b/desktop/src/desktop_interaction.rs
index b014bd86..e81198ce 100644
--- a/desktop/src/desktop_interaction.rs
+++ b/desktop/src/desktop_interaction.rs
@@ -5,7 +5,7 @@ use winit::{
 };
 
 use massive_animation::{Animated, Interpolation};
-use massive_applications::{InstanceId, ViewEvent, ViewRole};
+use massive_applications::{InstanceId, InstanceParameters, ViewEvent, ViewRole};
 use massive_geometry::PixelCamera;
 use massive_input::Event;
 use massive_renderer::RenderGeometry;
@@ -31,6 +31,7 @@ pub enum UserIntent {
         //
         // Idea: What about looking for which presenter has the focus currently?
         originating_instance: Option<InstanceId>,
+        parameters: InstanceParameters,
     },
     StopInstance {
         instance: InstanceId,
@@ -175,6 +176,7 @@ impl DesktopInteraction {
                     Key::Character(c) if c.as_str() == "t" => {
                         return Ok(UserIntent::StartInstance {
                             originating_instance: Some(instance),
+                            parameters: Default::default(),
                         });
                     }
                     Key::Character(c) if c.as_str() == "w" => {
diff --git a/desktop/src/instance_manager.rs b/desktop/src/instance_manager.rs
index 17584c86..f5158342 100644
--- a/desktop/src/instance_manager.rs
+++ b/desktop/src/instance_manager.rs
@@ -29,8 +29,6 @@ pub struct InstanceManager {
 #[derive(Debug)]
 struct RunningInstance {
     application_name: String,
-    #[allow(dead_code)]
-    creation_mode: CreationMode,
     events_tx: UnboundedSender<InstanceEvent>,
     views: HashMap<ViewId, ViewInfo>,
 }
@@ -107,7 +105,6 @@ impl InstanceManager {
             instance_id,
             RunningInstance {
                 application_name: application.name.clone(),
-                creation_mode,
                 events_tx,
                 views: HashMap::new(),
             },
diff --git a/desktop/src/lib.rs b/desktop/src/lib.rs
index de7c6f11..9aa2b93f 100644
--- a/desktop/src/lib.rs
+++ b/desktop/src/lib.rs
@@ -19,6 +19,7 @@ pub use desktop_interaction::*;
 pub use desktop_presenter::DesktopPresenter;
 pub use event_router::{EventRouter, EventTransition, HitTester};
 
+
 // A layout helper.
 // Robustness: Can't we implement ToPixels somewhere?
 
diff --git a/desktop/src/projects/configuration/toml_reader.rs b/desktop/src/projects/configuration/toml_reader.rs
index d3ada21a..aff448dd 100644
--- a/desktop/src/projects/configuration/toml_reader.rs
+++ b/desktop/src/projects/configuration/toml_reader.rs
@@ -3,11 +3,10 @@ use std::collections::HashMap;
 use anyhow::Result;
 use indexmap::IndexMap;
 use serde::Deserialize;
+use serde_json::Map;
 use toml::Value;
 
-use super::types::{
-    GroupContents, LaunchGroup, LaunchProfile, LayoutDirection, Parameter, Parameters, ScopedTag,
-};
+use super::types::{GroupContents, LaunchGroup, LaunchProfile, LayoutDirection, ScopedTag};
 
 /// Intermediate representation for deserializing TOML configuration files.
 #[derive(Debug, Deserialize)]
@@ -71,23 +70,18 @@ fn build_launch_profile(
     groups: &[String],
 ) -> Result<LaunchProfile> {
     let mut tags = Vec::new();
-    let mut params = Vec::new();
+    let mut params = Map::new();
 
     for (key, value) in section {
-        let value = toml_value_to_string(&value)?;
-
         if groups.contains(&key) {
+            let value = toml_value_to_string(&value)?;
             tags.push(ScopedTag::new(key, value));
         } else {
-            params.push(Parameter::new(key, value));
+            params.insert(key, serde_json::to_value(&value)?);
         }
     }
 
-    Ok(LaunchProfile {
-        name,
-        params: Parameters(params),
-        tags,
-    })
+    Ok(LaunchProfile { name, params, tags })
 }
 
 /// Build a cross-product hierarchy of groups at the given depth level.
@@ -224,7 +218,7 @@ datacenter = "ber"
 
         assert_eq!(app_ref.name, "host-1");
         assert_eq!(app_ref.params.len(), 1);
-        assert_eq!(app_ref.params[0].name, "command");
+        assert!(app_ref.params.contains_key("command"));
         assert_eq!(app_ref.tags.len(), 2);
         assert!(app_ref.tags.iter().any(|t| t.scope == "datacenter"));
         assert!(app_ref.tags.iter().any(|t| t.scope == "type"));
@@ -323,14 +317,14 @@ datacenter = "ber"
     }
 
     fn app(name: &str, params: &[(&str, &str)], tags: &[(&str, &str)]) -> LaunchProfile {
+        let mut param_map = Map::new();
+        for (k, v) in params {
+            param_map.insert(k.to_string(), serde_json::Value::String(v.to_string()));
+        }
+
         LaunchProfile {
             name: name.to_string(),
-            params: Parameters(
-                params
-                    .iter()
-                    .map(|(k, v)| Parameter::new(k.to_string(), v.to_string()))
-                    .collect(),
-            ),
+            params: param_map,
             tags: tags
                 .iter()
                 .map(|(scope, tag)| ScopedTag::new(scope.to_string(), tag.to_string()))
diff --git a/desktop/src/projects/configuration/types.rs b/desktop/src/projects/configuration/types.rs
index 2d020756..ba63646b 100644
--- a/desktop/src/projects/configuration/types.rs
+++ b/desktop/src/projects/configuration/types.rs
@@ -1,4 +1,5 @@
-use derive_more::Deref;
+use serde_json::{Map, Value};
+
 use massive_layout::LayoutAxis;
 
 #[derive(Debug)]
@@ -34,7 +35,7 @@ pub enum GroupContents {
 #[derive(Debug, Clone)]
 pub struct LaunchProfile {
     pub name: String,
-    pub params: Parameters,
+    pub params: Map<String, Value>,
     pub tags: Vec<ScopedTag>,
 }
 
@@ -52,17 +53,3 @@ impl ScopedTag {
         }
     }
 }
-
-#[derive(Debug, Deref, Clone, Default)]
-pub struct Parameters(pub Vec<Parameter>);
-
-#[derive(Debug, Clone)]
-pub struct Parameter {
-    pub name: String,
-    pub value: String,
-}
-impl Parameter {
-    pub fn new(name: String, value: String) -> Self {
-        Self { name, value }
-    }
-}
diff --git a/desktop/src/projects/launcher_presenter.rs b/desktop/src/projects/launcher_presenter.rs
index c3f9ac92..0943de71 100644
--- a/desktop/src/projects/launcher_presenter.rs
+++ b/desktop/src/projects/launcher_presenter.rs
@@ -148,6 +148,7 @@ impl LauncherPresenter {
                 // Usability: Should pass this rect?
                 return Ok(UserIntent::StartInstance {
                     originating_instance: None,
+                    parameters: self.profile.params.clone(),
                 });
             }
             ViewEvent::CursorEntered { .. } => {
diff --git a/desktop/src/projects/mod.rs b/desktop/src/projects/mod.rs
index 45e047c6..a1a78498 100644
--- a/desktop/src/projects/mod.rs
+++ b/desktop/src/projects/mod.rs
@@ -6,9 +6,7 @@ use log::warn;
 
 use crate::{
     band_presenter::BandTarget,
-    projects::configuration::{
-        GroupContents, LaunchProfile, LayoutDirection, Parameters, ScopedTag,
-    },
+    projects::configuration::{GroupContents, LaunchProfile, LayoutDirection, ScopedTag},
 };
 
 mod configuration;
@@ -72,7 +70,7 @@ impl Default for ProjectConfiguration {
                 content: GroupContents::Profiles(
                     [LaunchProfile {
                         name: DEFAULT_PROFILE.into(),
-                        params: Parameters::default(),
+                        params: Default::default(),
                         tags: Vec::new(),
                     }]
                     .into(),