Upated backport so that it works on Racket 7 pre-release

experimental/template.rkt

@@ -1,4 +1,6 @@
 #lang racket/base
+(require version-case (for-syntax racket/base))
+(version-case [(version< (version) "6.90.0.24") ;; not exactly the precise version number I think
 (require (for-syntax racket/base
                      "dset.rkt"
                      racket/syntax
@@ -658,3 +660,54 @@ instead of integers and integer vectors.
    (cond [(zero? n) x]
          [else (stx-drop (sub1 n) (stx-cdr x))]))
  )
+]
+[else
+(require (for-syntax racket/base)
+         (only-in racket/private/template
+                  metafunction))
+(provide (rename-out [syntax template]
+                     [syntax/loc template/loc]
+                     [quasisyntax quasitemplate]
+                     [quasisyntax/loc quasitemplate/loc]
+                     [~? ??]
+                     [~@ ?@])
+         define-template-metafunction
+         syntax-local-template-metafunction-introduce)
+
+;; ============================================================
+;; Metafunctions
+
+(define-syntax (define-template-metafunction stx)
+  (syntax-case stx ()
+    [(dsm (id arg ...) . body)
+     #'(dsm id (lambda (arg ...) . body))]
+    [(dsm id expr)
+     (identifier? #'id)
+     (with-syntax ([(internal-id) (generate-temporaries #'(id))])
+       #'(begin (define internal-id (make-hygienic-metafunction expr))
+                (define-syntax id (metafunction (quote-syntax internal-id)))))]))
+
+(define current-template-metafunction-introducer
+  (make-parameter (lambda (stx) (if (syntax-transforming?) (syntax-local-introduce stx) stx))))
+
+(define old-template-metafunction-introducer
+  (make-parameter #f))
+
+(define ((make-hygienic-metafunction transformer) stx)
+  (define mark (make-syntax-introducer))
+  (define old-mark (current-template-metafunction-introducer))
+  (parameterize ((current-template-metafunction-introducer mark)
+                 (old-template-metafunction-introducer old-mark))
+    (define r (call-with-continuation-barrier (lambda () (transformer (mark (old-mark stx))))))
+    (unless (syntax? r)
+      (raise-syntax-error #f "result of template metafunction was not syntax" stx))
+    (old-mark (mark r))))
+
+(define (syntax-local-template-metafunction-introduce stx)
+  (let ([mark (current-template-metafunction-introducer)]
+        [old-mark (old-template-metafunction-introducer)])
+    (unless old-mark
+      (error 'syntax-local-template-metafunction-introduce
+             "must be called within the dynamic extent of a template metafunction"))
+    (mark (old-mark stx))))
+])

info.rkt

@@ -1,7 +1,8 @@
 #lang info
 (define collection "backport-template-pr1514")
 (define deps '("base"
-               "rackunit-lib"))
+               "rackunit-lib"
+               "version-case"))
 (define build-deps '("scribble-lib" "racket-doc"))
 (define scribblings '(("scribblings/backport-template-pr1514.scrbl" ())))
 (define pkg-desc "Description Here")