diff --git a/congame-core/components/dsl.rkt b/congame-core/components/dsl.rkt
index 0ca785c..0297544 100644
--- a/congame-core/components/dsl.rkt
+++ b/congame-core/components/dsl.rkt
@@ -38,22 +38,21 @@
      (dsl-require* src id)]))
 
 (define (dsl-require* src id)
-  (let ([src (regexp-replace #rx"#lang conscript/local" src "#lang conscript")])
-    (log-dsl-debug "dsl-require: ~a" (~.s #:max-width 1024 src))
-    (unless (regexp-match? #rx"^#lang conscript *\r?\n" src)
-      (error 'dsl-require "only #lang conscript is supported"))
-    (define path #f)
-    (dynamic-wind
-      (lambda ()
-        (set! path (make-temporary-file "conscript-dsl-~a.rkt")))
-      (lambda ()
-        (call-with-output-file path
-          #:exists 'truncate/replace
-          (lambda (out)
-            (display src out)))
-        (begin0 (dynamic-require `(file ,(path->string path)) id)
-          (module-cache-clear!)
-          (collect-garbage)))
-      (lambda ()
-        (with-handlers ([exn:fail:filesystem? void])
-          (delete-file path))))))
+  (log-dsl-debug "dsl-require: ~a" (~.s #:max-width 1024 src))
+  (unless (regexp-match? #rx"^#lang conscript *\r?\n" src)
+    (error 'dsl-require "only #lang conscript is supported"))
+  (define path #f)
+  (dynamic-wind
+    (lambda ()
+      (set! path (make-temporary-file "conscript-dsl-~a.rkt")))
+    (lambda ()
+      (call-with-output-file path
+        #:exists 'truncate/replace
+        (lambda (out)
+          (display src out)))
+      (begin0 (dynamic-require `(file ,(path->string path)) id)
+        (module-cache-clear!)
+        (collect-garbage)))
+    (lambda ()
+      (with-handlers ([exn:fail:filesystem? void])
+        (delete-file path)))))
diff --git a/congame-example-study/conscript-archetype1.rkt b/congame-example-study/conscript-archetype1.rkt
index 16679b3..8cd2e73 100644
--- a/congame-example-study/conscript-archetype1.rkt
+++ b/congame-example-study/conscript-archetype1.rkt
@@ -1,4 +1,4 @@
-#lang conscript/local
+#lang conscript
 
 (provide
  hya54)
diff --git a/congame-example-study/conscript-examples.rkt b/congame-example-study/conscript-examples.rkt
index 18dd974..f95d653 100644
--- a/congame-example-study/conscript-examples.rkt
+++ b/congame-example-study/conscript-examples.rkt
@@ -1,4 +1,4 @@
-#lang conscript/local
+#lang conscript
 
 (require racket/format) ; -> provides ~r
 
diff --git a/congame-example-study/conscript-local-shared.rkt b/congame-example-study/conscript-local-shared.rkt
deleted file mode 100644
index a0da86a..0000000
--- a/congame-example-study/conscript-local-shared.rkt
+++ /dev/null
@@ -1,27 +0,0 @@
-#lang conscript/local
-
-(defvar*/instance counter the-counter)
-
-(defstep (hello)
-  @md{# Welcome to the study
-
-      @button{Continue}})
-
-(defstep (increment)
-  (when (undefined? counter)
-    (set! counter 0))
-  (define (do-increment)
-    (with-study-transaction
-      (set! counter (+ counter 1))))
-  @md{# Press the Button to Increment the Counter
-
-      Counter: @format["~a" counter]
-
-      @button[do-increment]{Continue}})
-
-(defstep (end)
-  @md{# You're done})
-
-(defstudy the-study
-  [hello --> increment --> end]
-  [end --> ,(lambda () done)])
diff --git a/congame-example-study/conscript-local-transitions-and-image/img/code-screenshot.png b/congame-example-study/conscript-local-transitions-and-image/img/code-screenshot.png
deleted file mode 100644
index 27f52d2..0000000
--- a/congame-example-study/conscript-local-transitions-and-image/img/code-screenshot.png
+++ /dev/null
@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:9a8eddef6d016f6de909c4081323cdced38d238fcfcf205653a59e9495e4cb44
-size 60980
diff --git a/congame-example-study/conscript-local-transitions-and-image/study.rkt b/congame-example-study/conscript-local-transitions-and-image/study.rkt
deleted file mode 100644
index 058df11..0000000
--- a/congame-example-study/conscript-local-transitions-and-image/study.rkt
+++ /dev/null
@@ -1,65 +0,0 @@
-#lang conscript/local
-
-(provide
- transition-study)
-
-(defvar consent?)
-
-(define-static-resource images "img")
-
-(defstep (step-a)
-  @md{# Step A
-
-      @button[#:to-step-id 'step-c]{Go to Step C}
-      @button{Go to Step B}})
-
-(defstep (step-b)
-  @md{# Step B
-
-      @button{Go to Step C}})
-
-(defstep (step-c)
-  (define (render-slider _idx name value)
-    `(input
-      ([name ,name]
-       [type "range"]
-       [min "0"]
-       [max "100"]
-       [value ,(or value "50")])))
-
-  @md{# Step C
-
-      @form{
-        @checkbox[#:consent? #:required? #f]{Do you consent to continue?}
-        @binding[#:sliders (make-sliders 5 render-slider)]
-        @submit-button}})
-
-(defstep (consented)
-  @md{# Consented
-
-      Thanks for consenting to participate. As a thanks, watch this image:
-
-      @img[
-        #:alt "Screenshot of Code"
-        #:src (resource-uri images "code-screenshot.png")]
-
-      @button{Restart at Step A}})
-
-(defvar sliders)
-
-(defstep (not-consented)
-  @md{# Not Consented
-
-      Sorry to see you leave.
-
-      @~a[sliders]
-
-      @button[#:to-step-id 'step-a]{Restart at Step A}})
-
-(defstudy transition-study
-  [step-a --> step-b --> step-c --> ,(lambda ()
-                                       (if consent?
-                                           'consented
-                                           'not-consented))]
-  [consented --> step-a]
-  [not-consented --> not-consented])
diff --git a/congame-example-study/conscript-local.rkt b/congame-example-study/conscript-local.rkt
deleted file mode 100644
index 46effb9..0000000
--- a/congame-example-study/conscript-local.rkt
+++ /dev/null
@@ -1,56 +0,0 @@
-#lang conscript/local
-
-(defvar* shared-var
-  shared-var-unique-id)
-
-(defvar name)
-(defvar age)
-
-(defstep (hello)
-  @md{# Welcome to the study
-
-      You are participant @~a[(current-participant-id)].
-
-      @button{Continue}})
-
-(defstep (set-shared-var)
-  (set! shared-var 42)
-  @md{# Press the Button to Continue
-
-      @button{Continue}})
-
-(defstep (get-info)
-  @md{# Tell us about yourself
-
-      The value of the shared var is @format["~a" shared-var].
-
-      @form{@input-text[#:name]
-            @input-number[#:age]
-            @submit-button}})
-
-(defstep (end)
-  @md{# You're done
-
-      Name: @name
-
-      Age: @format["~a" @age]
-
-      @button{Continue}})
-
-(defstudy study-a
-  [hello --> set-shared-var --> get-info --> end]
-  [end --> ,(lambda () done)])
-
-(defstep (outer-hello)
-  @md{# Welcome to the Parent Study
-
-      @button{Continue}})
-
-(defstep (outer-end)
-  @md{# You're done!
-
-      Shared var: @format["~a" shared-var].})
-
-(defstudy study-b
-  [outer-hello --> study-a --> outer-end]
-  [outer-end --> outer-end])
diff --git a/congame-example-study/many-designs/ach91.rkt b/congame-example-study/many-designs/ach91.rkt
index de4af25..7271840 100644
--- a/congame-example-study/many-designs/ach91.rkt
+++ b/congame-example-study/many-designs/ach91.rkt
@@ -1,4 +1,4 @@
-#lang conscript/local
+#lang conscript
 
 ;; ACH91:
 ;;
diff --git a/congame-example-study/prisoners-dilemma.rkt b/congame-example-study/prisoners-dilemma.rkt
index fd3c5ca..6382e69 100644
--- a/congame-example-study/prisoners-dilemma.rkt
+++ b/congame-example-study/prisoners-dilemma.rkt
@@ -9,7 +9,6 @@
  prisoners-dilemma-model)
 
 ;; For next time:
-;; * Multiple participants & current owner in conscript/local
 ;; * Add bot support to conscript (default actions on all steps, figure out models)
 
 (defvar*/instance choices dilemma-choices)
diff --git a/conscript/base.rkt b/conscript/base.rkt
index e78c203..9364e77 100644
--- a/conscript/base.rkt
+++ b/conscript/base.rkt
@@ -130,7 +130,6 @@
   (define whitelist
     '(buid
       congame-web/components/uploaded-file
-      conscript/local/matchmaking
       conscript/matchmaking
       conscript/survey-tools
       gregor
diff --git a/conscript/info.rkt b/conscript/info.rkt
index 4f8c566..3b6d961 100644
--- a/conscript/info.rkt
+++ b/conscript/info.rkt
@@ -11,6 +11,7 @@
     "koyo-lib"
     "mime-type-lib"
     "net-lib"
+    "threading-lib"
     "web-server-lib"))
 (define build-deps
   '("rackunit-lib"))
diff --git a/conscript/local.rkt b/conscript/local.rkt
deleted file mode 100644
index 2eb29b2..0000000
--- a/conscript/local.rkt
+++ /dev/null
@@ -1,372 +0,0 @@
-#lang racket/base
-
-(require (for-syntax racket/base
-                     syntax/parse/pre)
-         (only-in congame/components/study
-                  make-study-participant
-                  done?
-                  next?)
-         (only-in (submod congame/components/study private)
-                  current-embed/url
-                  current-request
-                  current-return
-                  current-study-manager
-                  response/step
-                  study-manager
-                  study-steps
-                  step/study?
-                  step/study-study
-                  step-id
-                  step-handler
-                  step-transition
-                  study-name)
-         koyo/continuation
-         koyo/http
-         koyo/url
-         net/mime-type
-         net/sendurl
-         racket/async-channel
-         racket/match
-         racket/port
-         racket/unit
-         web-server/dispatch
-         (only-in web-server/http header request-bindings/raw request-uri response? response/output)
-         (only-in web-server/servlet send/back send/suspend/dispatch servlet-prompt)
-         web-server/servlet-dispatch
-         web-server/web-server
-         (prefix-in conscript: "base.rkt")
-         (except-in "base.rkt" defvar form)
-         "congame-sig.rkt"
-         "matchmaking-sig.rkt"
-         "matchmaking-unit.rkt")
-
-(provide
- (all-from-out "base.rkt"))
-
-
-;; preview ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(provide
- preview)
-
-(define (preview a-study [open-as-owner? #f])
-  (define seq (box 0))
-  (define port-or-exn-ch
-    (make-async-channel))
-  (define ((wrap-application-url handler) req)
-    (parameterize ([current-application-url-host "127.0.0.1"]
-                   [current-application-url-port port-or-exn])
-      (handler req)))
-  (define-values (app _reverse-uri)
-    (dispatch-rules
-     [("")
-      (lambda (req)
-        (define owner?
-          (not (not (bindings-ref (request-bindings/raw req) 'owner))))
-        (define participant-id
-          (let loop ([old (unbox seq)])
-            (if (box-cas! seq old (add1 old))
-                (add1 old)
-                (loop (unbox seq)))))
-        (define manager
-          (study-manager
-           (make-study-participant
-            #:id participant-id
-            #:user-id participant-id
-            #:instance-id participant-id)
-           #f))
-        (parameterize ([current-request req]
-                       [current-participant-id participant-id]
-                       [current-participant-owner? owner?]
-                       [current-study-manager manager])
-          (run-study a-study)))]
-     [("dsl-resource" (integer-arg) (string-arg) ...)
-      (lambda (_req _instance-id path-elements)
-        (define path
-          (apply build-path (current-directory) path-elements))
-        (response/output
-         #:mime-type (path-mime-type path)
-         #:headers (list (header #"content-length" (string->bytes/utf-8 (number->string (file-size path)))))
-         (lambda (out)
-           (call-with-input-file path
-             (lambda (in)
-               (copy-port in out)
-               (close-output-port out))))))]))
-  (define stop
-    (parameterize ([current-continuation-key-cookie-secure? #f])
-      (serve
-       #:port 0
-       #:listen-ip "127.0.0.1"
-       #:dispatch (dispatch/servlet
-                   (wrap-application-url
-                    (wrap-protect-continuations
-                     app)))
-       #:confirmation-channel port-or-exn-ch)))
-  (define port-or-exn
-    (sync port-or-exn-ch))
-  (when (exn:fail? port-or-exn)
-    (raise port-or-exn))
-  (send-url (format "http://127.0.0.1:~a~a" port-or-exn (if open-as-owner? "?owner=x" "")))
-  (with-handlers ([exn:break? void])
-    (sync never-evt))
-  (stop))
-
-(define (run-study a-study [req (current-request)])
-  (define paramz (current-parameterization))
-  (parameterize ([current-vars (or (current-vars) (make-hash))]
-                 [current-data (make-hash)]
-                 [current-stack (cons
-                                 (study-name a-study)
-                                 (current-stack))])
-    (let loop ([this-step (car (study-steps a-study))])
-      (if (not this-step)
-          `(continue ,paramz)
-          (match (run-step this-step req)
-            [(? response? res)
-             (send/back res)]
-            [`(to-step ,to-step-id ,paramz)
-             (define next-step
-               (find-step a-study to-step-id))
-             (call-with-parameterization paramz
-               (lambda ()
-                 (loop next-step)))]
-            [`(continue ,paramz)
-             (redirect/get/forget/protect)
-             (match ((step-transition this-step))
-               [(? done?)
-                `(continue ,paramz)]
-               [(? next?)
-                (call-with-parameterization paramz
-                  (lambda ()
-                    (loop (find-next-step a-study (step-id this-step)))))]
-               [next-step-id
-                (define next-step
-                  (find-step a-study next-step-id))
-                (call-with-parameterization paramz
-                  (lambda ()
-                    (loop next-step)))])])))))
-
-(define (run-step a-step [req (current-request)])
-  (define paramz #f)
-  (call-with-current-continuation
-   (lambda (return)
-     (send/suspend/dispatch/protect
-      (lambda (embed/url)
-        (parameterize ([current-embed/url
-                        (lambda (hdl)
-                          (embed/url
-                           (λ (req) ;; noqa
-                             (call-with-parameterization
-                               paramz
-                               (lambda ()
-                                 (parameterize ([current-request req])
-                                   (hdl req)))))))]
-                       [current-return return]
-                       [current-request req])
-          (set! paramz (current-parameterization))
-          (if (step/study? a-step)
-              (return (run-study (step/study-study a-step)))
-              (response/step a-step))))))
-   servlet-prompt))
-
-(define (find-next-step a-study id)
-  (let loop ([steps (study-steps a-study)])
-    (match steps
-      [(? null?) #f]
-      [`(,this-step ,next-step . ,_other-steps)
-       #:when (eq? (step-id this-step) id)
-       next-step]
-      [`(,_this-step . ,other-steps)
-       (loop other-steps)])))
-
-(define (find-step a-study id)
-  (define the-step
-    (for/first ([s (in-list (study-steps a-study))]
-                #:when (eq? (step-id s) id))
-      s))
-  (begin0 the-step
-    (unless the-step
-      (error 'find-step "step ~a not found" id))))
-
-
-;; stubs ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(provide
- defvar
- defvar*
- defvar*/instance
- defvar/instance
- put/identity
- form
- call-with-study-transaction
- with-study-transaction
- current-participant-id
- current-participant-owner?
- make-matchmaker
- get-ready-groups
- get-current-group
- reset-current-group)
-
-(define current-stack (make-parameter null))
-(define current-vars (make-parameter #f))
-(define current-instance-vars (make-parameter (make-hash)))
-(define current-data (make-parameter #f))
-(define current-participant-id (make-parameter #f))
-(define current-participant-owner? (make-parameter #f))
-
-(define-syntax (defvar stx)
-  (syntax-parse stx
-    [(_ id:id)
-     #`(begin
-         (define-syntax id
-           (make-set!-transformer
-            (lambda (stx)
-              (syntax-case stx (set!)
-                [(set! id v) #'(put-var 'id v)]
-                [id (identifier? #'id) #'(get-var 'id)])))))]))
-
-(define (get-var id)
-  (hash-ref
-   (current-data)
-   (list (current-stack) id)
-   undefined))
-
-(define (put-var id v)
-  (hash-set!
-   (current-data)
-   (list (current-stack) id)
-   v))
-
-(define-syntax (defvar/instance stx)
-  (syntax-parse stx
-    [(_ id:id)
-     #`(begin
-         (define-syntax id
-           (make-set!-transformer
-            (lambda (stx)
-              (syntax-case stx (set!)
-                [(set! id v) #'(put-var/instance 'id v)]
-                [id (identifier? #'id) #'(get-var/instance 'id)])))))]))
-
-(define (get-var/instance id)
-  (hash-ref
-   (current-instance-vars)
-   (list (current-stack) id)
-   undefined))
-
-(define (put-var/instance id v)
-  (hash-set!
-   (current-instance-vars)
-   (list (current-stack) id)
-   v))
-
-(define-syntax (defvar* stx)
-  (syntax-parse stx
-    [(_ id:id unique-id:id)
-     #`(begin
-         (define-syntax id
-           (make-set!-transformer
-            (lambda (stx)
-              (syntax-case stx (set!)
-                [(set! id v) #'(put-var* 'unique-id 'id v)]
-                [id (identifier? #'id) #'(get-var* 'unique-id 'id)])))))]))
-
-(define (get-var* uid k)
-  (hash-ref
-   (current-vars)
-   (cons uid k)
-   undefined))
-
-(define (put-var* uid k v)
-  (hash-set!
-   (current-vars)
-   (cons uid k)
-   v))
-
-(define-syntax (defvar*/instance stx)
-  (syntax-parse stx
-    [(_ id:id unique-id:id)
-     #`(begin
-         (define-syntax id
-           (make-set!-transformer
-            (lambda (stx)
-              (syntax-case stx (set!)
-                [(set! id v) #'(put-var*/instance 'unique-id 'id v)]
-                [id (identifier? #'id) #'(get-var*/instance 'unique-id 'id)])))))]))
-
-(define (get-var*/instance uid k)
-  (hash-ref
-   (current-instance-vars)
-   (cons uid k)
-   undefined))
-
-(define (put-var*/instance uid k v)
-  (hash-set!
-   (current-instance-vars)
-   (cons uid k)
-   v))
-
-(define (put/identity k v)
-  (put-var k v))
-
-;; FIXME: Refactor formular to be parameterized over the current put
-;; procedure to avoid duplicating some of these checks.
-(define-syntax (form stx)
-  (syntax-parse stx
-    [(_ {~alt
-         {~optional {~seq #:action action:expr}}
-         {~optional {~seq #:bot bot}}
-         {~optional {~seq #:fields fields}}} ...
-        body ...+)
-     #:attr default-action
-     (if (let uses-set!? ([stx stx])
-           (syntax-parse stx
-             #:literals (set!)
-             [(set! . _args) #t]
-             [(rator rand ...) (ormap uses-set!? (cons #'rator (syntax-e #'(rand ...))))]
-             [_ #f]))
-         #f
-         #'default-form-action)
-     (let check-loop ([inner-stx #'(body ...)])
-       (syntax-parse inner-stx
-         #:literals (form)
-         [(form . _args)
-          (raise-syntax-error 'form "forms cannot be nested" stx inner-stx)]
-         [(rator rand ...)
-          (for-each check-loop (cons #'rator (syntax-e #'(rand ...))))]
-         [_ (void)]))
-     #'(conscript:form
-        {~? {~@ #:action {~? action default-action}}}
-        {~? {~@ #:bot bot}}
-        {~? {~@ #:fields fields}}
-        body ...)]))
-
-(define default-form-action
-  (make-keyword-procedure
-   (lambda (kws kw-args . _args)
-     (for ([kwd (in-list kws)]
-           [arg (in-list kw-args)])
-       (put-var (string->symbol (keyword->string kwd)) arg)))))
-
-(define (call-with-study-transaction proc)
-  (proc))
-
-(define-syntax-rule (with-study-transaction body0 body ...)
-  (call-with-study-transaction
-   (lambda ()
-     body0 body ...)))
-
-(define-values/invoke-unit matchmaking@
-  (import congame^)
-  (export matchmaking^))
-
-(module reader syntax/module-reader
-  conscript/local
-  #:read (lambda (in) (do-read-syntax #f in))
-  #:read-syntax do-read-syntax
-  #:info (lambda (key defval proc)
-           ((dynamic-require 'conscript/tool 'get-info) key defval proc))
-  (require scribble/reader)
-  (define (do-read-syntax src in)
-    (parameterize ([current-readtable (make-at-readtable)])
-      (read-syntax src in))))