Here at Arbor Solutions, we take pride in staying up to date in the latest advancements but also want to make sure we can walk alongside our customers as they navigate new technologies and more. For example, for an IBM i (AS/400) programmer, the jump from Project BOB / BOB 1.0 to BOB 2.0 + Premium Package for IBM i is much more significant than a typical version upgrade. One of the primary reasons is that it changes BOB from a code assistant into an agent-based modernization platform specifically aware of IBM i technologies such as RPG, CL, DDS, COBOL, and Db2 for i. [heise.de], [itjungle.com], [nicklitten.com]
Let’s dive in together to compare the two and help you feel more prepared for the jump! We will start with some high-level stats about each.
BOB 1.0 versus BOB 2.0 Comparison
BOB 1.0
- AI coding assistant.
- Helpful for generating and explaining code.
- Limited IBM i specialization.
- Primarily worked like an enhanced chat/code generation tool.
- Less autonomous. [bob.ibm.com], [itjungle.com]
BOB 2.0
- Agentic AI platform.
- Can launch subagents to investigate code independently.
- Supports background and parallel tasks.
- Includes IBM i-specific workflows and tooling through the Premium Package for i.
Designed for modernization of large RPG and legacy applications. [itjungle.com], [nicklitten.com], [heise.de]
| Area | Original BOB | BOB 2.0 |
| Architecture | Separate foundations for IDE and shell experiences | Unified three-layer architecture (Agent, Harness, Clients) shared across all interfaces [bob.ibm.com], [itjungle.com] |
| Performance | Sequential operations and earlier-generation workflow model | Faster execution, parallel tool calling, larger context handling, improved responsiveness [bob.ibm.com], [itjungle.com], [nicklitten.com] |
| AI Agents | Primarily a single-agent experience | Supports subagents that can investigate tasks independently and return summaries to the main agent [bob.ibm.com], [itjungle.com] |
| Background Work | Limited | Can run tasks in the background while the developer continues other work [bob.ibm.com], [nicklitten.com] |
| Modes | Earlier workflow model | Simplified Agent, Plan, and Ask modes for execution, planning, and analysis [nicklitten.com] |
| Modernization | General code assistance | Stronger application modernization support for Java, IBM i, and IBM Z environments with dedicated premium packages [heise.de], [itjungle.com] |
| Enterprise Features | Basic assistant capabilities | Workflow automation, analytics, governance, and specialized modernization workflows |
Obvious Differences
Let talk about some of the differences that IBM i developers will notice most.
1. Native IBM i Awareness
With BOB 1.0, many IBM i developers had to explain platform-specific concepts repeatedly.
With BOB 2.0 Premium Package for i, IBM includes:
- RPG understanding
- CL knowledge
- COBOL support
- DDS support
- Db2 for i knowledge
- IBM i development conventions and best practices
The tool is now trained and configured with an IBM i-specific development mode rather than treating RPG as just another language. [nicklitten.com], [heise.de]
Example
BOB 1.0
- “Explain this RPG program.”
BOB 2.0
- Understands program structure, files, displays, business rules, IBM i conventions, and modernization patterns more accurately. [nicklitten.com], [heise.de]
2. Direct IBM i Connectivity
One of the biggest IBM i improvements is direct interaction with IBM i source.
BOB 2.0 Premium Package for i adds:
- Direct access to source members
- Library access
- Native IBM i workspace integration
This reduces the need to export source to external files before analysis. [nicklitten.com], [rpgpgm.com]
For shops still storing source in traditional source physical files, this is a substantial productivity improvement. [nicklitten.com]
3. RPG Modernization Workflows
BOB 1.0 could generate RPG code or explain it.
BOB 2.0 adds dedicated modernization workflows including:
- Fixed-format RPG to free-format RPG conversion
- Record-level access modernization
- RPG documentation generation
- Refactoring assistance
- Unit test generation
- Monolithic program decomposition
These are packaged as repeatable workflows rather than one-off prompts. [nicklitten.com], [heise.de]
Example
A 20,000-line RPG III application can be:
- Analyzed.
- Documented.
- Converted to free-form RPG.
- Reviewed for SQL conversion opportunities.
- Refactored into service programs.
All using predefined workflows. [nicklitten.com], [heise.de]
4. Subagents
This is arguably the most important architectural improvement.
BOB 2.0 can spawn specialized subagents that work independently on a task and then return results to the main agent. [bob.ibm.com], [itjungle.com]
For example, while examining a large ERP system, BOB can:
- Have one agent analyze database usage.
- Have another trace authentication logic.
- Have another document RPG business rules.
The main agent combines the findings. [bob.ibm.com], [itjungle.com]
BOB 1.0 generally handled this work serially and within a single context. [bob.ibm.com], [itjungle.com]
5. Background Tasks
In BOB 1.0 you generally waited while analysis completed.
In BOB 2.0:
- Long-running modernization tasks continue in the background.
- You can switch to other work.
- Multiple tasks can run simultaneously. [bob.ibm.com], [nicklitten.com]
For IBM i modernization projects that may involve thousands of source members, this is a major advantage. [nicklitten.com], [heise.de]
6. Better Understanding of Legacy Code
IBM states that BOB 2.0 is focused on understanding decades-old enterprise applications. The IBM i package includes curated IBM i documentation and modernization knowledge that helps the model understand older technologies and programming styles. [heise.de], [nicklitten.com]
This is particularly useful for:
- RPG II
- RPG III
- Early RPG IV
- DDS-based applications
- Legacy green-screen systems [nicklitten.com], [heise.de]
7. New Working Modes
BOB 2.0 introduces three primary modes:
Ask Mode
- Explain code.
- Analyze programs.
- Read-only investigations.
Plan Mode
- Explore requirements.
- Build modernization plans.
- Create migration strategies.
Agent Mode
- Execute changes.
- Generate code.
- Apply transformations.
This separation works particularly well for IBM i modernization projects where teams want to review plans before code is changed. [nicklitten.com], [heise.de]
8. Modernization Scope
BOB 1.0 was mostly a coding assistant.
BOB 2.0 is becoming a modernization platform supporting:
- RPG modernization
- IBM i application transformation
- Java modernization
- IBM Z / COBOL modernization
- Cloud migration preparation [heise.de], [itjungle.com]
Practical Bottom Line for an AS/400 Shop
If you’re maintaining RPG applications today:
BOB 1.0 helped you write code.
BOB 2.0 helps you transform systems.
The biggest IBM i-specific gains are:
- Native IBM i knowledge. [nicklitten.com]
- Direct access to IBM i source and libraries. [nicklitten.com], [rpgpgm.com]
- Automated fixed-to-free RPG conversion. [nicklitten.com]
- Legacy application documentation generation. [heise.de], [nicklitten.com]
- Autonomous subagents for large codebase analysis. [bob.ibm.com], [itjungle.com]
- Background execution of modernization tasks. [bob.ibm.com], [nicklitten.com]
For organizations with decades of RPG and DDS code, BOB 2.0 is aimed squarely at reducing the effort of understanding, documenting, and modernizing those applications rather than simply helping developers write new code. [heise.de], [itjungle.com], [nicklitten.com]
Reach out to the team at Arbor to talk more!