Abstract: An apparatus and program product generate difference data representative of modifications made to one release of a standard code base to facilitate the adaptation of later releases of the standard code base. The difference data is generated at least in part in connection with canonical parsing of a modified version of a release of a standard code base such that the difference data is representative of semantic changes made in the modified version.

Abstract: A rollback support method for transactions a node among nodes in a distributed system, including modifying a disposable cache copy of data as part of transaction, propagating a version state and/or a data state of the modified cache to any of the nodes, verifying non-violation of a transaction semantic and/or a replication policy relating to the transaction, committing the transaction to any nodes if successful, revising a version state of other reliable replicas and disposable cache copies in the system based on the version state of the modified disposable cache copy, the disposable cache copies being members of a membership-based view, and updating a data state of other reliable replicas in the system based on the data state of the modified copy, and aborting the transaction if it fails, including restoring the disposable cache copy based on any reliable replicas and/or disposable cache copies in the system.

Abstract: Methods and systems are provided in a group communication system for dynamically changing a version of a group communication protocol from a first version to a second version transparently to external sources and destinations. The system accommodates newly joining members that can only support versions of the protocol other than the version currently in use without interruption in service. Similarly, the system can upgrade its operating version of the group communication protocol to improve performance when a member having relatively low capabilities exits the group.

Abstract: An apparatus and program product generate difference data representative of modifications made to one release of a standard code base to facilitate the adaptation of later releases of the standard code base. The difference data is generated at least in part in connection with canonical parsing of a modified version of a release of a standard code base such that the difference data is representative of semantic changes made in the modified version.

Abstract: An apparatus, program product and method generate difference data representative of modifications made to one release of a standard code base to facilitate the adaptation of later releases of the standard code base. The difference data is generated at least in part in connection with canonical parsing of a modified version of a release of a standard code base such that the difference data is representative of semantic changes made in the modified version.

Abstract: Methods and systems are provided in a group communication system for dynamically changing a version of a group communication protocol from a first version to a second version transparently to external sources and destinations. The system accommodates newly joining members that can only support versions of the protocol other than the version currently in use without interruption in service. Similarly, the system can upgrade its operating version of the group communication protocol to improve performance when a member having relatively low capabilities exits the group.

Abstract: A rollback support method for transactions a node among nodes in a distributed system, including modifying a disposable cache copy of data as part of transaction, propagating a version state and/or a data state of the modified cache to any of the nodes, verifying non-violation of a transaction semantic and/or a replication policy relating to the transaction, committing the transaction to any nodes if successful, revising a version state of other reliable replicas and disposable cache copies in the system based on the version state of the modified disposable cache copy, the disposable cache copies being members of a membership-based view, and updating a data state of other reliable replicas in the system based on the data state of the modified copy, and aborting the transaction if it fails, including restoring the disposable cache copy based on any reliable replicas and/or disposable cache copies in the system.

Abstract: A hypertext display system is described in which displayed hypertext links contain a marker indicating whether or not the unit of information to which the link leads has previously been visited by the user, the system being characterized in that the user can cause the display of further information regarding previous visits to that unit of information via a predetermined user input operation at a time when a display cursor is located within the boundaries of the marker. Active markers or footprints are employed associated with links leading to nodes the user has already visited. In one implementation using a graphical user interface, these markers are icons for timestamp windows. The user can activate the markers in order to decide whether or not to revisit the node.

Abstract: A generalized link is provided in a data processing system to enable referencing from a point within an organized hierarchy of an on-line softcopy text, to an arbitrary multimedia object. The multimedia object may be represented by data which is also contained within the softcopy book or alternately which may be separate from the book as a separate file or a separate data base. This enables an author at the time of writing the softcopy book, to specify specific multimedia hardware and software support for the display of multimedia presentations accompanying the text in the book. Provision is made for the author to specify alternate forms of multimedia presentation, where a particular specified multimedia apparatus or supporting software is not present at a workstation. An improved method for dynamically updating a softcopy book to a new edition is also disclosed.