RRGparbank

To change a label, click on a node to select a different label from a list. The syntactic category and the function tag (before and after the dash "-") must be selected separately by clicking on the corresponding part of the label.
To add a function tag to a node that does not have one yet, drag it from the list of function tags onto the node.
Re-attach a node by dragging and dropping it on a new parent. This can be used to created discontinuous constituents.
Similarly, nodes can be removed and new ones added by dragging to/from below the tree.
Finally, the bracketing can be edited manually in the text box below the tree; press "validate" to update the tree. Whitespace is ignored. Each token must have a dedicated POS tag.

				[...wait for it...]

(SENTENCE
  (CLAUSE
    (CORE
      (NP (PRO 0=It))
      (NUC
        (AUX-TNS 1=was)
        (V 2=composed)
        (ADVP-PERI
          (CORE_ADV
            (NUC_ADV
              (ADVP-PERI (CORE_ADV (NUC_ADV (ADV 3=almost))))
              (ADV 4=entirely)))))
      (PP
        (P 5=of)
        (NP
          (CORE_N
            (NUC_N
              (N 6=words)
              (CLAUSE-PERI
                (PrCS (NP-REL (PRO-REL 7=that)))
                (CORE
                  (NP (PRO 8=we))
                  (ADVP-PERI (CORE_ADV (NUC_ADV (ADV 9=already))))
                  (NUC (V 10=possess))))))
          (NP-PERI
            (CORE_N
              (NUC_N (N 11=words))
              (PP-PERI
                (CORE_P
                  (NUC_P (P 12=like))
                  (NP
                    (NP (CORE_N (NUC_N (N 13=hit))) (, 14=,))
                    (NP (CORE_N (NUC_N (N 15=run))) (, 16=,))
                    (NP (CORE_N (NUC_N (N 17=dog))) (, 18=,))
                    (NP (CORE_N (NUC_N (N 19=tree))) (, 20=,))
                    (NP (CORE_N (NUC_N (N 21=sugar))) (, 22=,))
                    (NP (CORE_N (NUC_N (N 23=house))) (, 24=,))
                    (NP (CORE_N (NUC_N (N 25=field))))))))))))
    (. 26=-))
  (CLAUSE
    (CLM 27=but)
    (CORE
      (PP-PERI
        (CORE_P
          (NUC_P (P 28=in))
          (NP
            (CORE_N
              (NUC_N (N 29=comparison))
              (PP
                (CORE_P
                  (NUC_P (P 30=with))
                  (NP
                    (OP-DEF 31=the)
                    (CORE_N
                      (AP-PERI (CORE_A (NUC_A (A 32=present-day))))
                      (AP-PERI (CORE_A (NUC_A (A 33=English))))
                      (NUC_N (N 34=vocabulary))))))))))
      (NP (OP-DEF 35=their) (CORE_N (NUC_N (N 36=number))))
      (NUC
        (AUX-TNS 37=was)
        (ADVP-PERI (CORE_ADV (NUC_ADV (ADV 38=extremely))))
        (A 39=small)))
    (CLAUSE-PERI
      (, 40=,)
      (CLM 41=while)
      (CORE
        (NP (OP-DEF 42=their) (CORE_N (NUC_N (N 43=meanings))))
        (NUC (AUX-TNS 44=were) (V 48=defined))
        (ADVP-PERI
          (CORE_ADV
            (NUC_ADV
              (ADVP-PERI
                (CORE_ADV
                  (NUC_ADV
                    (ADV 45=far)
                    (ADVP-PERI (CORE_ADV (NUC_ADV (ADV 46=more)))))))
              (ADV 47=rigidly)))))))
  (. 49=.))