Harnessing IFL and Linux for Accelerated Mainframe Delivery with PopUp Mainframe

Today’s enterprises span mission-critical industries such as financial services, logistics, retail, and government, many of which continue to rely on the IBM Mainframe for its unparalleled resilience and processing power—especially in light of advancements like the AI-enabled IBM Z17. However, software delivery on the mainframe is often slowed by environment availability, siloed team structures, and lack of flexible tooling. Gary Thornhill, Founder and CEO of PopUp Mainframe, presented at Tech Field Day Extra at SHARE Cleveland 2025 to address these issues. His solution centers on PopUp Mainframe, a platform designed to provision virtual mainframe environments quickly across a range of hardware—from IFLs and LinuxONE on IBM Z systems to cloud-hosted and x86 environments—making mainframe development and testing faster, more agile, and accessible.

The PopUp Mainframe platform emulates full Z environments for non-production use and helps alleviate bottlenecks in development cycles by enabling organizations to replicate environments in under 10 minutes. It supports automated provisioning, rollback, and snapshot capabilities through its FastTrack feature, ensuring rapid, repeatable testing and development. Thornhill emphasized the platform’s flexibility to run where customers already have compute capacity—including air-gapped environments or the cloud—supported by a floating license model that allows dormant environments to be spun up only when needed. Critically, running on IFLs offers a 5-10x performance gain versus x86 platforms, leveraging the power of z/Architecture while maintaining total separation from production workloads. Licensing restricts PopUp’s use solely for dev/test purposes, addressing IBM’s compliance policies while giving developers hands-on access to real data (masking supported) and real workloads without regulatory or security compromises.

Security and compatibility are key components of the PopUp proposition. The platform is pre-integrated with IBM, BMC, and open-source tools and supports broader ecosystems including Broadcom and Rocket Software solutions. PopUp maintains full ZOS compatibility regardless of code age or complexity, from modern subsystems to legacy stacks. Mainframe teams gain the ability to serialize and isolate development pipelines and shift left without incurring infrastructure procurement overhead. Integration with tools like VS Code, Galasa, and COBOL Check helps extend modern DevOps practices to mainframe, enabling continuous integration and delivery. Users can securely push clones into any environment, even cloud, backed by persistent ZFS snapshots which achieve 90% disk compression and utilize commodity storage in place of expensive DASD. As Thornhill explained, PopUp allows organizations to quadruple delivery speed, reduce emissions, lower cost, and improve compliance by centralizing masking and maintaining data governance entirely on-Z. PopUp is not just an emulator—it’s a strategic enabler for agile mainframe modernization.