A method performed by a system comprising at least one first client terminal and a plurality of second client terminals connected to a network, the method comprising: creating (S105) a first content, in response to an operation on one of the at least one first client terminal; assigning a unique first address on the network to the first content; displaying the first content at a display of each of the two second client terminals; editing (S307, S309) the displayed first content assigned with the unique first address, in response to an operation on each of the two second client terminals; storing (S312, S315), in a storage, the first contents edited at each of the two second client terminals as two second contents corresponding to the two second client terminals; and assigning (S313) two unique second addresses on the network to the two second contents; characterized by permitting (S302) access to the unique first address from two of the second client terminals among the second client terminals, each of which is anonymous, and on each of which an authentication process without an ID that identifies a user who uses a web service is performed by determining whether a correct password associated with the unique first address has been received from the two second terminals, and in response to determining that any one of the second client terminals has indicated that any one of the second contents associated with the one second client terminal is in an edit completion state, storing (S319), in the storage, the one second content in a non-editable state in association with any one of the unique second addresses associated with the one second client terminal and in association with information which indicates the edit completion state. creating (S105) a first content, in response to an operation on one of the at least one first client terminal; assigning a unique first address on the network to the first content; displaying the first content at a display of each of the two second client terminals; editing (S307, S309) the displayed first content assigned with the unique first address, in response to an operation on each of the two second client terminals; storing (S312, S315), in a storage, the first contents edited at each of the two second client terminals as two second contents corresponding to the two second client terminals; and assigning (S313) two unique second addresses on the network to the two second contents; characterized by permitting (S302) access to the unique first address from two of the second client terminals among the second client terminals, each of which is anonymous, and on each of which an authentication process without an ID that identifies a user who uses a web service is performed by determining whether a correct password associated with the unique first address has been received from the two second terminals, and in response to determining that any one of the second client terminals has indicated that any one of the second contents associated with the one second client terminal is in an edit completion state, storing (S319), in the storage, the one second content in a non-editable state in association with any one of the unique second addresses associated with the one second client terminal and in association with information which indicates the edit completion state. <EOS>