① Explainer · Escrow
Released mainframe source you cannot build is a comfort, not a protection. The rights that keep you running through a vendor failure or acquisition are perpetual fallback licenses, verified deposits, and support transition terms. Escrow is one part of continuity, not the whole of it.
Software escrow places source code and build materials with a neutral agent, to be released to you if a defined event occurs: vendor bankruptcy, product discontinuation, or a failure to maintain. The promise is continuity. If the vendor disappears, you hold the means to keep the software alive. That is the theory, and it reads well in a risk register.
The reality on the mainframe is harder. Mainframe products commonly depend on specialized build chains, proprietary assemblers, and deep platform skills that few buyers still keep in house. A source deposit you cannot compile, or could compile but never safely change, protects nothing. Escrow earns its place only when the deposit is verified and buildable and you have a real right to use it. Otherwise it is a line item that feels like insurance without being it.
Continuity is a bundle of rights, not a single escrow agreement. The matrix below ranks the five that do the real work, with what each protects and the drafting weakness to watch. Source escrow sits among them, not above them.
| Right | What it protects | Common weakness |
|---|---|---|
| Perpetual fallback license | Right to keep running after termination | Drafted to lapse on termination |
| Current version use rights | Indefinite use of the deployed release | Tied to active maintenance only |
| Verified source escrow | Means to maintain if vendor disappears | Unverified, stale, or unbuildable deposit |
| Support transition obligation | Knowledge transfer and run book handover | No defined period or deliverables |
| Change of control protection | Terms survive an acquisition intact | Assignment freely permitted to acquirer |
The single most valuable right for most buyers is the perpetual fallback license, the right to keep running the current version even after the contract ends. It protects continuity without ever needing the source. Escrow becomes meaningful only once that base is secured and the deposit is independently verified as complete and buildable.
| Scenario | Primary protection | Why |
|---|---|---|
| Vendor acquired by a competitor | Change of control and fallback license | Acquirer may sunset or reprice the product |
| Vendor ceases trading | Verified escrow plus current version rights | You must self maintain or freeze safely |
| Product discontinued, vendor survives | Support transition obligation | You need an orderly handover, not source |
| Maintenance dispute, vendor live | Perpetual fallback license | Keep running while the dispute resolves |
Most real continuity events are acquisitions and discontinuations, not bankruptcies, which is exactly where a bare source escrow helps least. Matching the right to the scenario you actually face, rather than buying escrow reflexively, is the difference between protection and paperwork.
Continuity gaps bite at acquisition time, and the mainframe market has seen plenty of consolidation. When a tool changes hands, the new owner often revisits pricing, support, and roadmap. Buyers who negotiated only an unverified escrow find they have a deposit they cannot use and no fallback license to keep running on their own terms. The optimization is to treat continuity as a negotiated bundle at signing, weighted toward the rights that keep you operating.
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Related explainers: mainframe software audit clauses, sysplex vs standalone pricing differences, and the IPLA one time charge model where perpetual rights already exist. Buyer guide: divestiture and mainframe license separation. Commercial: contract review and license negotiation. Hub: the Software AG buyer side guide.
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