Amalgamated likelihood estimation (ALE) is a probabilistic approach to exhaustively explore all reconciled gene trees that can be amalgamated as a combination of clades observed in a sample of gene trees. We implement the ALE approach in the context of a reconciliation model (cf. http://arxiv.org/abs/1211.4606 ), which allows for the duplication, transfer and loss of genes. We use ALE to efficiently approximate the sum of the joint likelihood over amalgamations and to find the reconciled gene tree that maximizes the joint likelihood among all such trees.
Here I am pretty sure that the correct return code should be 0. Maybe the same issue is present in other programs as well?