The invention concerns a computer-implemented collaboration platform comprising: means enabling an initiator (158) to create a message (168); means enabling the initiator (158) to invite a group of first degree partners (160, 162, 164) to respond to the message (168); means enabling a first degree partner (162) to create a sub-message (170, 172); means adapted to automatically create a link between the sub-message (170) and the message (168), or between the first degree partner (162) and the initiator (158), or between collaboration spaces established for the sub-message (170) and the message (168); and means enabling the first degree partner (162) to invite a group of second degree partners (176) to respond to the sub-message (170) while concealing identities of one or more first degree partner (158, 160, 164) for the group of second degree partners (176), and/or vice versa concealing identities of one or more second degree partner (176) for the group of first degree partners (158, 160, 164).